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2000 STEEP III Final ReportRESEARCH PROJECT
TITLE: Residue Production and Retention in Small Grain Cereal and
Legume Rotational Systems with Different Tillage Practices. INVESTIGATORS: Stephen Guy, Extension
Crop Management Specialist, Dept. of Plant, Soil and Entomological Sciences
(PSES), UI FINAL REPORT: COPPERATORS: Wayne Jensen, Art Schultheis, Nathan and Steve Riggers, Eric Hasselstrom, Randy and Larry Keatts, Richard Druffel, Larry Cochran, Bob Garrett (growers) and Roy Patten and Brad Bull (UI Plant Science Farm) PROJECT OBJECTIVES:
KEY WORDS:: Tillage, residue, rotation, integrated management systems STATEMENT OF PROBLEM: Winter wheat established after legumes using conventional tillage systems can leave the soil vulnerable to erosion. About 65-75% of annual precipitation falls after wheat seeding when plants are small and can occur during freeze-thaw cycles. Erosion can be reduced with greater residue cover and soil roughness, and improved water infiltration. Residue cover is usually most effective. Growers have reduced tillage before planting winter wheat after legumes, but fragile legume residues and low residue production often leave little soil cover over winter. Surface residue levels going into winter wheat could be increased by carrying over spring cereal residue grown before the legume crop. However, spring cultivations are often indicated for incorporation of many legume herbicides. After fall and spring tillage, little cereal crop residue remains to carry through winter wheat planting. Conventional tillage practices for legume production can also increase soil compaction in wet spring condition, reducing water infiltration and increasing erosion potential. ZONE OF INTEREST: Higher precipitation Palouse region of ID and WA. ABSTRACT OF RESEARCH FINDINGS: Eight on-farm trials were conducted with field scale equipment in cooperation with growers in eastern Washington and northern Idaho to compare a variety of tillage and residue management systems for establishing spring peas in a cereal - pea - winter wheat rotation sequence. Compared to more intensive tillage or residue removal systems, spring direct seeding of peas resulted in higher surface residue levels for improved erosion protection after planting spring pea and subsequent winter wheat crops, similar stand establishment and equal or higher yields of pea and subsequent winter wheat crop. In other tillage trials, there was not adequate residue from the previous pea crop alone when plowing is done before the pea crop, but when previous cereal residue is carried through the pea crop, adequate residue is maintained through winter wheat seeding. Pea and lentil residue can survive adequately through winter wheat establishment and the greater the tillage intensity, the less surface groundcover. Herbicide experiments within some of these trials indicate that imazamox can injure peas. Fall versus spring application of imazethapyr did not result in differences in weed control or pea yields. No benefit was seen for direct seeded peas receiving small amounts of starter fertilizer N, P, and/or S at planting. No soil moisture differences were seen between direct seeding and more intensive tillage treatments at the trial where this data was collected. Dry pea 'Pro 2100' yielded more seed and crop residue than 'Columbia' pea. Both pea varieties yielded more than 'Brewer' or 'Crimson' lentil and produced twice as much residue. There was adequate residue on the surface only after direct-shank N application before seeding and no-till seeding of winter wheat following pea, and only in no-till following lentil. When cereal residue was carried through legume seeding using reduced tillage systems, the cereal residue did not significantly change in ground cover extent over winter, and in one trial contributed 35% of the residue groundcover after winter wheat was seeded. In these trials, legume and winter wheat yields were not significantly influenced by reduced tillage. Herbicide evaluations have not shown any adverse weed control effects of reduced tillage before pea seeding. However, no-till of pea did increase soil impedance above 8 inches. Compared to more
intensive tillage or residue removal systems, spring direct seeding of
peas resulted in higher surface residue levels for improved erosion protection
after planting spring pea and subsequent winter wheat crops, and equal
or higher yields of both crops if no pest problems were encountered. There
was crop damage to wheat from meadow voles in no-till due to extremely
high rodent infestations. There was no injury apparent to winter wheat
from any pea herbicide treatment. There were higher wheat yields in reduced
disturbance treatments in some cases. These trials show that yields of
both pea and the following wheat crop can be as good and sometimes better
under direct seeding cropping compared to conventional systems. There
are many values to reduced tillage and even more so to direct seeding
systems shown in these studies including: soil conservation, ease of operation,
and reduced cost. These studies support the viability of direct seeding
systems in the higher rainfall areas of the Palouse when pest and equipment
problems can be adequately managed. Earlier results from these studies
can be found in the 1998 STEEP progress report. RESULTS AND INTERPRETATION: Objective 1: Evaluation
of Legume Grain Crop for Residue with Various Tillage Intensity. Lead
by Stephen Guy All crops of the
1997-1998 trial performed well (Table 1). Pro 2100 pea yielded more seed
and than the lentils and Columbia pea. The pea cultivars produced more
than twice the crop residue than the lentils. However, the ground cover
after the four legumes was not very different after tillage was done and
throughout the rest of winter wheat establishment. Increasing tillage
intensity did decrease the residue ground cover following all four legume
treatments. After planting winter wheat on October 7, the groundcover
did not change as much following pea, but seems to decline faster for
the lentil residue over-winter. Lentil residue also seems to be buried
more easily by tillage. Winter wheat yields averaged 122 bushels per acre
and test weight averaged 59.3 pounds per bushel. No significant differences
were found among crop or tillage treatments for wheat performance. Table 1. Crop yields and residue with different tillage intensity following legume crops at the UI Kambitsch Farm, Genesee, ID, 1997-1998
Objective 2: Spring
Cereal Residue Persistance with Four Tillages and Subsequent Crop Performance.
Lead by Stephen Guy In the 1996-1998 trial, after fall tillage, groundcover was followed through the winter and pea seeding in the spring (Table 3). Residue levels remained nearly constant through the winter with a tendency to decline slightly in the spring. Lowest residue levels were following plowing that gave a 'black soil'. Residue groundcover following chisel and paratill treatments were not different at any sample date and the no-till give the highest levels. Residue levels declined due to preparation for and seeding of pea as shown in the 20-May levels. After pea harvest, the ground was cultivated and winter wheat seeded with a double-disc drill. Residue levels were low and limited cereal residue from the 1996 cereal crop provided limited groundcover. Table 3. Yields and performance in a cereal residue carryover through a pea crop trial at the UI Kambitch Farm, Genesee, ID
In the 1996-1998
trial, the spring cereal crops did not yield as much as desired due to
poor seeding conditions followed by dry weather (Table 4). The residue
groundcover was lower than desired, but the barley was higher than the
wheat. The pea crop did not establish as well as desired in the direct
seed treatment due to limitations on soil penetration by the drill. The
winter wheat crop did establish well and was productive. A greater amount
of cereal residue was carried over through the pea crop in the no-till
than in all other tillage systems and averaged about 600 lb/a higher.
Wheat yields in 1998 were not different for tillage or 1996 crop and averaged
107 bu/a.
Groundcover residue
measurements in the 1997-1999 trial were taken over-winter following the
spring cereal crops (Table 5). In all cases after the spring cereal crops,
there was more groundcover in direct seeding than in paratill, which had
more than the chisel and the plow treatment was lowest. That relationship
held through pea planting. After pea harvest, direct seeding was highest
and was also greater than plow after winter wheat planting. These trials
show the practicality of carrying spring cereal residue through the pea
crop and having adequate residue groundcover after paratill and direct
seeding, but not when plowing before pea. This is true even when wheat
is seeded in a low disturbance system of shank-and-seed. The pea crop
alone does not provide adequate residue. Table 5. Groundcover
residue levels in the cereal residue carryover through pea crop trials
at the UI Kambitsch Farm, Genesee, ID, 1997-1999
In the 1997-1999 trial, the spring cereal crops did well (Table 6). The barley was near the county average and spring wheat was low due to a high infestation of Hessian Fly. However, the Hessian Fly infestation did not lower the residue from the spring wheat. The pea crop was established well with no differences in pea population among tillages or previous crop. Pea yields were highest in no-till and paratill and lowest in the plow treatment. More cereal residue was carried through wheat seeding in this trial with 2300 lb/a in no-till after pea harvest. Within the paratill treatment, pea following wheat yielded 339 lb/a more than following barley. Winter wheat was established following the pea crop but suffered extensive rodent damage over winter. Wheat yields were highest in chisel and paratill. The no-till wheat yields were probably affected by the rodent damage. Table 6. Yields
and performance in a cereal residue carryover through a pea crop trial
at the UI Kambitsch Farm, Genesee, ID, 1997-1999
These trials show the practicality of carrying spring cereal residue through the pea crop and having adequate residue groundcover after paratill and direct seeding, but not after plowing. This happens even with a low disturbance wheat seeding like shank-and-seed. The pea crop does not provide adequate residue. With good pea stands, the yields in no-till can be greater than for plow. Pest control and stand establishment problems are two challenges to direct seeding and no-till systems that will need further research and careful management to overcome. Grower On-Farm
Trials on Direct Seed Systems for Peas. The grower large-scale trials were established and managed with their field equipment. All the trials were conducted for a 2-year period beginning in the fall after harvest of a spring or winter cereal, through a pea crop and the subsequent winter wheat crop. Nearly all the trials compare a spring direct seed system without prior tillage with some type of fall minimum tillage and direct seeding in the spring without any spring tillage. Some of the trials included additional tillage and residue management treatments to address specific grower's interests and equipment available. All trials have four replications of each treatment and individual plots range from 30 to 50 feet wide and 700 to 1,500 feet long. Surface residue evaluations were conducted after fall tillage of the cereal crop, before and after pea planting, after pea harvest and after winter wheat planting. Other data collection included pea plant stand and yield, and finally winter wheat yield. Wayne Jensen - Genesee, ID -- A crop residue management study comparing 1995 fall plow - spring cultivate - seed, fall chisel - spring direct seed, and fall flail-chisel - spring direct seed treatments after 90 bu/A spring wheat was conducted. Soil moisture and temperature were not different before seeding of the pea crop. Residue was higher in the chisel treatments throughout the study (Table 7). Peas were planted in 1996 and did not yield differently due to tillage. In the chisel treatments, over 35% of the residue after the pea crop came from spring wheat. Residue groundcover varied little over-winter after planting wheat and wheat yields were not different among tillage treatments. This trial shows the benefit of reducing the tillage on cereal residue before a pea crop to carry some of that residue forward to protect the soil after winter wheat seeding without impact on pea or wheat yield. Table 7. Tillage comparisons following 1995 spring wheat through 1996 pea and 1997 winter wheat crops, Wayne Jensen Farm, Genesee, ID Art Schultheis - Colton, WA - A comparison of direct spring seeding of lentils after harrow versus cultivation after harrow and before seeding was started in spring 1997. The stubble of the spring barley was disked in early fall and chiseled/harrowed in late fall. Residue levels and lentil crop performance was not different for the two spring treatments (Table 8). This study shows that tillage before seeding lentils can be reduced with no adverse effects on lentil performance and reduces potential for soil compaction. Under many conditions this may increase the previous crop residue on the lentil fields. Table 8.
Spring tillage comparison after barley before lentil Art Schultheis farm,
Colton, WA Wayne Jensen - Genesee, ID -- The 2-year trial comparing two tillage practices for spring pea following a 70 bu/A hard white spring wheat was completed in 1998 on the Wayne Jensen farm northwest of Genesee, ID (Table 6). The two treatments following hard white spring wheat were 1) Fall Plow-Spring Cultivate-Seed - fall (1996) moldboard plow with trash boards - spring Pursuit herbicide application and 2X cultivation - seed; and 2) Fall Chisel/Cultivate - Spring Direct Seed - fall chisel - late fall cultivate/harrow - spring Roundup-Pursuit herbicide application - spring direct seed. Both treatments were seeded with a John Deere 455 offset double disc drill. The soft white winter wheat crop was direct seeded that fall with a Yielder double disc drill. The results of this trial are very similar to the results of the other Jensen trial. The results from this trial show that the minimum fall tillage - direct spring seed system resulted in greater erosion protection with higher surface residue levels after seeding peas and the subsequent winter wheat crop than with the fall plow treatment, 34 vs.6% and 47 vs.30%, respectively (Table 9). There were no differences in plant establishment, pea yield or yield of the following winter wheat crop. Table 9. Tillage comparison following spring wheat through 1997 spring pea and 1998 winter wheat crops, Wayne Jensen, Genesee, ID - 20-to 24-inch rainfall zone.
Nathan and Steve Riggers - Nezperce, ID -- Four tillage and residue management systems were compared following a 65 bu/A hard red spring wheat crop west of Nezperce, ID in a 24- to 26-inch rainfall zone (Table 5). Treatments included: 1) Direct Spring Seed; 2) Spring Burn - Direct Spring Seed; 3) Fall Disc - Direct Spring Seed; 4) Fall Moldboard Plow - Spring Cultivate - Seed The two treatments with over-winter stubble received a late October application of Roundup. In early April, all treatments except the plow treatment received a second Roundup treatment about 2.5 weeks before planting. All treatments were seeded to 'Karita' pea with a Flexi-Coil 5000 no-till hoe air-seeder on May 4. Karita is a semi-leafless variety that stands upright and can be harvested with a standard grain header. All the plots were harrowed with a tine harrow after seeding. All treatments received separate post-emergence applications of Basagran and Assure II. Winter wheat was direct seeded in the fall with the same Flexi-Coil 5000 airseeder. Residue groundcover levels and pea yield was highest in the non-burn, direct seed systems (Table 10). Surface residue cover after pea and winter wheat planting were highest in the non-burn, direct seeded pea treatments at 72 and 60%, respectively. Pea emergence was not significantly different among the treatments, but lower than expected because the low seed lot germination (<85%) was not known at planting. Direct seed pea yield was significantly higher than burn-direct seed and plow treatments, with yields in the trial increasing with increasing surface residue levels. However, there were no significant differences in winter wheat yield and test weight in 1999. Table 10. Comparison of four tillage and residue management practices following 1997 hard red spring wheat through 1998 spring pea and 1999 winter wheat crops, Nathan and Steve Riggers, west of Nezperce, ID - 24- to 26-inch rainfall zone.
Randy and Larry Keatts - Lewiston, ID -- Five tillage and residue management practices were compared for spring pea following a 1997 soft white spring wheat crop south of Lewiston, ID in a 12- to 16-inch rainfall zone (Table 11). Previous crops were winter wheat (1996), and spring pea (1995). Treatments included: 1) Spring Direct Seed; 2) Spring Burn - Spring Direct Seed; 3) Fall Disc - Spring Direct Seed; 4) Fall Subsoil/Disc - Spring Direct Seed - fall R & R subsoiler - fall disc - direct seed; 5) Fall Chisel - Spring Direct Seed - fall chisel/harrow - direct seed. The trial received mid-October and early March applications of Roundup. All treatments were seeded to Columbia pea (common type) on March 18 with a Tye no-till disc drill, then harrowed and rolled. Winter wheat was seeded in the fall with a 2-pass system of direct-shank application of fertilizer and then seeding with the Tye no-till disc drill. Pea plant stand in the direct seed treatment was lower that most of the other treatments and a difference in seeding depth between fall-tilled treatments and the direct seed treatment in undisturbed residue probably caused the reduced plant stand. The field trial was seeded as one field and it was difficult to set seeding depth accurately for all treatments. Consequently, direct seed plots in undisturbed residue were seeded shallower than desired (0.5-1 inch) and tilled plots were seeded slightly deeper than desired (2-3 inch). Reduced seed-to-soil contact from shallow seeding in the direct seed treatment in standing stubble contributed to the lower stand. Pea yield was not significantly different among treatments. A hailstorm shortly before harvest resulted in approximately 60-70% seed loss. The direct seed treatment maintained the highest percent surface residue for erosion control after pea and winter wheat planting, 83 and 49%, respectively. There were no significant differences in winter wheat yield and test weight. Table 11: Comparison of tillage and residue management practices following a 1997 soft white spring wheat crop through 1998 spring pea and 1999 winter wheat crops. Randy and Larry Keatts, Lewiston, ID - 12- to 16-inch rainfall zone.
Art Schultheis
- Colton, WA -- Two tillage systems were compared for establishing
a 1998 spring pea crop following a 90 bu/A 1997 winter wheat crop just
northwest of Colton in a 20- to 22-inch annual rainfall zone (Table 12).
Previous rotation crops were lentils in 1996 and spring barley in 1995.
Treatments include: 1) Fall Disc-Subsoil - Spring Direct Seed - fall (1997)
John Deere disc-ripper - spring harrow - direct seed; and 2) Spring Direct
Seed. The winter wheat stubble was flailed after harvest when the residue
was dry. Roundup was applied on the direct seed treatments in the fall
and on both treatments in the early April. The trial was seeded in late
April to Columbia pea with a Flexi-Coil single-disc air seeder. The disc-rip
treatments were harrowed after seeding. Basagran and Thistrol were applied
post emergence to the disc-rip treatments only (no weeds observed at that
time on the direct seed treatments). Assure II was applied to both treatments
for grass weed control. Winter wheat was direct seeded with a John Deere
750 single disc no-till drill in the fall. Differences in winter wheat yields and test weights in 1999 were not statistically significant. There was a trend toward a lower average yield following direct seed peas, which was due primarily to a higher infestation of downy brome compared to following pea establishment after fall disc-ripping because of the winter wheat - pea - winter wheat rotation sequence. Yields under direct seeding on two of the replications were reduced by about 16 bu/A compared to the disc-ripper treatment, where downy brome infestation was the heaviest, but only 2-4 bu/A in two other replications with lighter weed levels. Note that the main point of this trial was to evaluate pea establishment methods following a high residue crop such as winter wheat, and not to evaluate direct seeding in a winter wheat - pea - winter wheat rotation. The study reemphasizes years of research and grower experience on the importance of two years out of winter cereals under direct seed system in order to minimize problems with winter annual grass weeds like downy brome in the following winter wheat crop. Table 12: Comparison of tillage practices following a 1997 soft white winter wheat crop through 1998 spring pea and 1999 winter wheat crops. Art Schultheis, Colton, WA - 20- to 22-inch annual rainfall zone.
Larry Cochran - Colfax, WA --Two tillage practices were compared for establishing a 1998 spring pea crop after a 1997 spring barley crop northeast of Colfax in a 18- to 20-inch annual rainfall zone (Table 13). Treatments included: 1) Fall Chisel/Cultivate/Harrow - Spring Direct Seed; and 2) Spring Direct Seed. Roundup was applied in late fall and in mid April. All treatments were direct seeded to Columbia peas on May 1 with a John Deere 750 single disc no-till drill then rolled. Winter wheat was direct seeded with the same John Deere 750 no-till drill in the fall. Direct seeding retained higher surface residue levels after pea and winter wheat planting, 84 vs. 43% and 55 vs. 43%, respectively, although both systems provided good erosion protection. Pea plant stands, yields and residue cover after pea harvest were not significantly different. There were also no significant differences in winter wheat yield and test weight in 1999. Table 13: Comparison of tillage practices following a 1997 spring barley crop through 1998 spring pea and 1999 winter wheat crops. Larry Cochran, Colfax, WA - 18- to 20-inch annual rainfall zone.
Bob Garrett - Endicott, WA -- Two tillage practices were compared for establishing a 1998 spring pea crop after 1997 soft white winter wheat crops northwest of Endicott in a 15- to 18-inch annual rainfall zone (Table 14). Treatments on the winter wheat fields included: 1) Fall Chisel/harrow - Spring Direct Seed - fall (1997) chisel (with narrow fertilizer knife openers on 12-inch spacing) and attached tine harrow - direct seed, and 2) Spring Direct Seed. Roundup was applied in mid-November and on March 22. Both treatment systems on the winter wheat field trial were direct seeded to Columbia peas on April 16 using a Great Plains no-till drill with coulters directly ahead of offset double discs. All plots were harrowed after seeding. Sencor was applied post-plant pre-emergence and Assure II and Basagran were applied post emergence as a tank mix about 5 weeks after seeding. Winter wheat was established in the fall using a 2-pass system with the same low-disturbance chisel as a direct-shank fertilizer applicator and seeding with the Great Plains no-till disc drill. Although there were slightly higher surface residue levels pre-plant and post-plant in spring peas under direct seeding compared to fall chisel/harrow - direct seed, no differences were noted later in pea plant stands, pea yield or in surface residue levels after pea harvest and winter wheat seeding. The fall chisel/harrow was a very low-disturbance operation, so both systems provided effective erosion protection in the pea crop and subsequent winter wheat crop. Seeding depth was generally 0.5 to 1 inch, slightly shallower than planned, contributing to lower plant stands than expected. Although the reasons for the low pea yields are not known, post-emergence herbicide injury is suspected as one factor in reducing plant growth and yield potential in both trials. There were no significant differences in winter wheat yield and test weight in 1999. Very dry growing season conditions, winter injury and a moderate to heavy downy brome infestation significantly reduced yield potential. No differences in down brome infestations were noted between the two tillage systems for pea establishment. As mentioned in the Schultheis trial above, the main point of this trial was to evaluate pea establishment methods following a high residue crop such as winter wheat, and not to evaluate direct seeding in a winter wheat - pea - winter wheat rotation. The study reemphasizes years of research and grower experience on the importance of two years out of winter cereals under direct seed system in order to minimize problems with winter annual grass weeds like downy brome. An identical trial being conducted in a nearby field in a spring wheat - pea -winter wheat sequence had a very low downy brome population. Unfortunately, harvest of the 1999 winter wheat crop in the trial was not possible due to mis-communications in re-staking the trial. Table 14:
Comparison of two tillage practices following a 1997 soft white winter
wheat crop through 1998 spring pea and 1999 winter wheat crops, Bob Garrett,
Endicott, WA - 15- to 18-inch annual rainfall zone.
These large scale field trials demonstrate that direct seeding of spring peas after cereals can significantly increase surface residue retention for erosion control and water storage through the cereal - grain legume - winter wheat rotation compared to more intensive tillage systems beginning with fall tillage. In addition, pea stand establishment and yield with direct seeding were either not significantly different or were greater than with fall tillage. In the winter wheat crops in the second year of the field trials, there were no significant differences in yield due to the tillage and residue management operations evaluated for grain legume establishment. Economic comparisons have also not been completed, but production costs may be reduced with spring direct seeding by eliminating a number of tillage operations. Wheat Yield Following
Pea with Various Tillage Regimes and Herbicide Treatments. In the fall of 1997, herbicide trials were established in the existing tillage blocks of two of the STEEP III trials described above. Selected for the herbicide trials were the Riggers site near Craigmont and the UI Kambitsch Farm 1997-99 cereal residue carryover study near Genesee. Imazethapyr (Pursuit; applied pre-emergence), imazethapyr/pendimethalin (Pursuit Plus; applied pre-emergence) and imazamox ("Raptor" for soybeans, applied post emergence) were evaluated for pea injury and pea seed yield at Nezperce and Genesee. The experiment was a split plot design with four replications. Herbicides were applied at 10 gpa with a tractor mounted sprayer. The herbicide subplots were 15 feet wide by the width of the tillage strip main plots (Table 15.) Table 15. Herbicide application data.
Visual injury from imazamox treatments was similar at both locations even though UAN was not added to the imazamox treatments at Nezperce because of the injury seen at Genesee. Pea plants were chlorotic 5 to 7 days after imazamox application and were shortened about 5 inches, and flowering was delayed and reduced. However, seed yield was reduced more at Genesee, 43% and 60%, than Nezperce, 8% and 28%, for imazamox at 0.032 and 0.064 lb/acre, respectively, compared to the highest yielding treatment (Table 16). Table 16. Pea seed yield averaged over tillage. There was no herbicide treatment by tillage regime interaction. Pea seed yield averaged over herbicide treatment was lowest from the plow treatment at both locations (Table 17). Winter wheat was
planted in September 1998 to determine carry-over effects on wheat injury
and grain yield. Table 17. Pea seed yield averaged over herbicide treatment.
Imazethapyr and imazethapyr/ pendimethalin (applied pre-emergence) and imazamox (applied post emergence) were applied to spring pea at Nezperce, Genesee, and Winchester, Idaho in spring 1998. The experiment was a split block design with four replications. The main plot tillage regimes were fall moldboard plow/spring cultivate, fall disc, spring burn, and direct seed at Nezperce; fall moldboard plow, fall chisel, fall paratill, and direct seed at Genesee; and burn, flail, disc, and direct seed at Winchester. The herbicide plots were 15 ft wide by the width of the tillage strip that varied from 20 to 46 ft depending on the tillage operation. Winter wheat was planted in September 1998 to determine herbicide carry-over effects on wheat injury and grain yield. Wheat was harvested at maturity in late summer 1999. Wheat was not visibly injured by any herbicide treatment and there were no herbicide treatment by tillage regime interactions for grain yield and test weight. Herbicide treatment did not reduce grain yield or test weight compared to the untreated control when averaged over tillage regime (Table 18). Test weight at Nezperce was lowest in the control plot when averaged over tillage regime, and test weight was not affected by herbicide treatment at the other locations. Grain yield, averaged over herbicide, treatment was higher in direct seed and burn plots than disc or moldboard plow plots at Nezperce; was higher in paratill and chisel plots at Genesee; and was highest in burn plots and lowest in flail plots at Winchester (Table 19). Lower yield in the direct seed plots compared to paratill and chisel at Genesee likely was a result of high rodent activity due to high residue. High yield in burn plots at Winchester also is likely a result of low residue. Test weight was highest at Winchester in the direct seed plots, and test weight was not affected by tillage regime at other locations. Table 18.
Wheat grain yield and test weight averaged over tillage.
Table 19. Wheat grain yield and test weight averaged over herbicide treatment.
Fall and spring
applied imazethapyr for no-tillage and conventionally tilled dry peas. Herbicide trials were established in the existing tillage blocks of two STEEP III trials in the fall of 1997. Selected for the herbicide trials were the Druffel site near Pullman and the Garrett site near Endicott (see above for tillage description and general plot management). The experimental design was a randomized complete block, split plot design with tillage as the whole plots and herbicide treatments as subplots. The three herbicide treatments were non-treated and fall or spring applications of 0.047 lb a.i. imazethapyr/acre. Fall herbicides were applied on Dec. 5, 1997 with temperature of 29 0F air and 32 0F soil and a relative humidity of 93%. Spring applications were on Feb. 25, 1998 with temperature of 45 0F air and 39 0F soil and a relative humidity of 79%. An unintended blanket application of imazethapyr over a portion of the Druffel herbicide study area in the spring of 1998 made any information from the site unusable and the herbicide study at this site was abandoned. Weed density was measured on June 8, 1998 at the Garrett site. Density measurements consisted of counting all weeds in four randomly selected one square foot areas within each subplot. Weeds were grouped as grass or broadleaf weeds. Plots were harvested on Aug. 6, 1998. Seed from plots were cleaned and weighed. Broadleaf weed densities
were not significantly different for tillage or herbicide treatment factors
nor the interaction (Table 20). Broadleaf weed densities were low at this
site. Grass weed densities were greater in direct seeding than in the
fall chisel-harrow treatment. However, grass density was not significantly
different for herbicide treatments or the interaction of tillage and herbicide
treatment. Table 20. Weed density and pea yield near Endicott, WA, 1998
The experiment continued through production of the 1998-1999 winter wheat crop using the original plots established in the fall of 1997. The original design of a randomized complete block split-plot with tillage treatments as whole plots and herbicide treatments as subplots was continued. The goal of year 2 of the study was to determine if the original imazethapyr applications for weed control in dry peas had any impact on the following winter wheat crop. Tillage treatments were applied as appropriate following the 1998 dry pea harvest. No additional herbicide treatments were applied following dry pea harvest or in the winter wheat crop. Weeds were controlled across the entire experimental area as needed during winter wheat production in 1998/99. Winter wheat stand counts and plant heights were taken on May 20, 1999 (Table 21). Additionally, final total winter wheat biomass and grain yields were measured on July 30, 1999. Results indicated no significant differences for any of the measured parameters for the main effects of tillage and herbicide treatments or the interactions. Thus, any residual herbicide that remained from fall 1997 or spring 1998 imazethapyr applications prior to dry pea production did not have an impact on winter wheat crop vigor as measured by stand density and plant height. Also, the mature winter wheat biomass and grain yield was not affected by either imazethapyr application in dry peas. Table 21.
Impact imazethapyr application timing for peas on winter wheat follow
crop.
Pea Soil Fertility
Experiments: The fertility component of the trials investigated starter (20 lb/acre) rates of N, P, and S in all possible combinations. In both the tilled and direct seed treatments, the fertilizers were band applied 2" directly below the seed at planting time. Experimental observations included plant stand, harvest yield, above?ground biomass at harvest (check and the N + P + S fertilizer treatment only), and 1000?seed weight (check and the N + P + S fertilizer treatment only). At both the Riggers and Schultheis sites, there were no significant responses to any fertilizer treatment (Table 22). In addition at these two sites, yields of the fall tillage (chisel plow or disk ripper)-spring direct seed plots were equal to the direct seed plots without fall tillage (Table 23). Sample analysis has not been completed from the Garrett and Druffel sites. Table 22. Dry pea yield as affected by combinations of N, P, and S fertilizer at 20 lb/ac.
Table 23. Dry pea yield as affected by tillage and fertility treatments on the Craigmont and Colton sites.
Starter applications of N, P, and S were tested under tilled and no-till seeding systems at two locations during the 1999 growing season. One site was located near Colfax, WA on Larry Cochran's farm and the other near Colton, WA on Art Schultheis' farm. The previous crop was spring barley and winter wheat at Colfax and Colton respectively. Tillage at Colfax consisted of fall chisel plowing and spring cultivating (standard field cultivator) while a disk ripper and a heavy harrow were used for fall and spring tillage at the Colton site. Both no-till and tilled plots were planted with a double disk, no-till plot drill on a 7.5" spacing using Columbia peas. The fertility component
of the trials investigated starter (20 lb/acre) rates of N, P, and S in
all possible combinations. In both the tilled and no-till treatments,
the fertilizers were band applied 2" directly below the seed at planting
time. Experimental observations included plant stand, harvest yield, above
ground biomass at harvest (check and the N + P + S fertilizer treatment
only), and 1000-seed weight (check and the N + P + S fertilizer treatment
only). Table 24. Dry pea yield as affected by tillage and fertility treatments on the Colfax site. Soil Water and
Physical Properties: Lead by John Hammel. Figure A. Profile soil-water content distributions during the 1998 growing season under the two tillage treatments near Colton, WA
Soil physical properties were measured to evaluate effects of tillage. Soil impedance (SI) and bulk density were measured in the spring of 1997 at two sites, the spring cereal residue carryover trial at the UI Kambitsch Farm near Genesee and the 1996-1997 trial with Wayne Jensen. Soil impedance was measured with a soil penetrometer to a depth of 20 inches. Bulk density of the soil surface layer (0-4") was measured with a surface density gauge. At the Jensen site, SI and bulk density of the chisel treatment was greater than the plow treatment (Figure 1). This is due primarily to the greater soil disturbance achieved with the moldboard plow compared to the shallower, less inversive chisel treatment. These differences in SI and bulk density, however were not significant. At the Kambitsch site, soil physical properties reflected the depth and type of tillage (Figure 2). No-till had the highest levels of SI within the soil surface zone affected by tillage (0-8"). Values of SI in the no-till treatment were approximately two times greater than SI values within the other tillage treatments. No substantial differences in SI were found among plow, chisel and paratill treatments. Bulk densities of the soil surface layer (0-4") were not significantly different among tillage treatments, although no-till had the highest bulk density.
Fig. 1. Soil impedance and surface layer bulk density results comparing plow and chisel tillage treatments.
Fig. 2. Soil impedance
and surface layer bulk density results comparing plow, no-till, paratill
and chisel tillage treatments. PUBLICATIONS,
PRESENTATIONS AND OTHER EDUCATIONAL EFFORTS: Refereed Publications Guy S.O. and D.B. Cox. 2001. Reduced tillage reduces residue groundcover in subsequent dry pea and winter wheat crops. Agronomy Journal (submitted). Pacific Northwest
Extension Publications Veseth, R.J., S.O.
Guy, D. Thill, J. Hammel, T. Fiez, J. Yenish. 1997. New minimum tillage
systems for legume-winter wheat cropping sequence. PNW Conservation Tillage
Handbook Series No. 20, Chap.2. PNW Extension publication in Idaho, Oregon
and Washington. Veseth, R., S. Guy, D. Cox, D. Thill, J. Hammel, T. Fiez, and J. Yenish. 1999. Direct Seed Systems for Grain Legumes - Pursuing Improved Erosion Control, Water Storage, Yields and Profitability. Pacific Northwest Conservation Tillage Handbook Series No. 26, Chap. 2. PNW Extension publication in Idaho, Oregon and Washington. Proceedings Veseth, R.J. June
1997. Direct seed pea/lentil tour. The Growers' Guide. Colfax, WA Veseth, R.J., S.O.
Guy, D. Thill, J. Hammel, T. Fiez, J. Yenish. 1997. New minimum tillage
systems for legume-winter wheat cropping sequence. June 1997 Field day
proceedings: Highlights of Research Progress. Washington State Univ. Dept.
of Crop and Soil Sciences Technical Rpt. 97-1 Veseth, R.J., S.O.
Guy, D. Thill, J. Hammel, T. Fiez, J. Yenish. 1997. New minimum tillage
systems for legume-winter wheat cropping sequence. June 1997 Field Day
Research and Extension Report. Univ. of Idaho, Dept. of Plant, Soil and
Entomological Sci. Guy, S., J. Hammel,
R. Veseth, D. Thill, T. Fiez, and J. Yenish. 1998. Residue Production
and Retention in Small Grain Cereal and Legume Rotational Systems with
Different Tillage Systems. In Strategies, Techniques and Tactics Guaranteed
to Increase Your No-Till Profits - National No-Tillage Conference, St.
Louis, Missouri, Jan 21-23, 1999, sponsored by No-Till Farmer, Brookfield,
WI. pg. 73-80. Guy, S., J. Hammel,
R. Veseth, D. Thill, T. Fiez, and J. Yenish. 1998. Residue Production
and Retention in Cereal and Legume Rotational Systems with Different Tillage
Systems. In Proceedings of the Northwest Direct Seed Intensive Cropping
Conference. Pasco, WA Veseth, R. June 1998.
Direct Seed and Minimum Tillage Systems for Grain Legumes. 1998 Field
Day Proceedings: Highlights of Research Progress. Washington State Univ.
Dept. of Crop and Soil Sciences Technical Rpt. 98-2. Veseth, R., D. Cox, S. Guy, J. Hammel, D. Thill, T. Fiez, and J. Yenish. 1999. Grower Direct Seed Pea Trials in Eastern Washington and Northern Idaho. In Proceedings of Northwest Direct Seed Cropping Systems Conference and Trade Show. Jan. 5-7, 1999, Spokane, WA. pg. 183-191. University Research
and Extension Reports Veseth, R.J., S.O.
Guy, D. Thill, J. Hammel, T. Fiez, J. Yenish. October 1997. New minimum
tillage systems for legume-winter wheat cropping sequence. The Growers'
Guide, Colfax, WA Veseth, R., S. Guy,
D. Cox, D. Thill, J. Hammel, T. Fiez, and J. Yenish. June 1999. Direct
Seed Systems for Grain Legumes -- Pursuing Improved Erosion Control, Water
Storage, Yields and Profitability. Published in both the 1999 Field Day
Proceedings: Highlights of Research Progress. Washington State Univ. Dept.
of Crop and Soil Sciences Technical Rpt. 99-1, Pullman, WA; and the 1999
University of Idaho Dept. of Plant, Soil and Entomological Sciences 1999
Field Day Research and Extension Rpt., Moscow, ID. Guy, S., D. Thill,
R. Veseth, J. Hammel, T. Fiez, J. Yenish, and D. Cox. 1999. Residue production
and retention in small grain cereal and legume rotational systems with
different tillage practices. P. 35-54. In 1998 STEEP III Annual Report.
Jan 6-8, 1999. University of Idaho, Agricultural Experiment Station, Moscow,
ID Guy, S., D. Cox,
R. Veseth, L. Smith and K. Hart. 1998. 1998 Idaho On-Farm Test Results.
University of Idaho, Cooperative Extension System, Progress Report No.
325 Campbell, J. and D. Thill. 1999. Pre- and post-emergence herbicide treatments applied to spring pea with tillage regimes. West. Soc. Weed Science Research Progress Report. P. 152 Popular Publications
-- Ag Media Veseth, R.J. 1998.
Crop Rotation Economics and Strategies for Direct Seeding. Reprinted in
Nov. 1998 The Growers' Guide, Colfax, WA; and Dec. 1998 USA Dry Pea and
Lentil Council Bulletin, Moscow, ID. Veseth, R.J., S. Guy, D. Cox, D. Thill, J. Hammel, T. Fiez and J. Yenish. June 1999. Direct Seed Systems for Grain Legumes - Pursuing Improved Erosion Control, Water Storage, Yields and Profitability. The Growers' Guide, Colfax, WA 1997 Direct Seed
Pea/Lentil Field Tour The half-day morning tour began at the UI Kambitsch Research Farm with an overview of this STEEP III project by Guy, who also lead tours of field trials on fall tillage effects on spring cereal residue carryover through a spring pea crop, and on legume crop and varietal differences in residue production and retention through winter wheat establishment under different tillage systems. Hammel discussed preliminary soil physical measurements and changes due to tillage and measurements that will be done in the trials. Fiez explained plans for pea fertility research across the large-scale grower trials planned for 1998 and 1999. The 1995-1997 and 1996-1998 field trials on the Wayne Jensen farm were toured by the group. Joan Campbell explained the herbicide research on Jensen's trial and plans for future weed control research plans across the large-scale grower trials over the next two years. In addition to the project research trials, the tour included six stops at direct seed pea/lentil fields described by Jensen and Schultheis. Tours of Field Research Trials -- (1) Lewis County Crops and Conservation Tour June 30, 1998 - This tour, beginning in Nezperce, ID, was sponsored by Lewis Co. Cooperative Extension System and Soil Conservation District, and was attended by over 55 area growers and Ag fieldmen. The project trial on the Nathan and Steve Riggers farm was highlighted. Roger Veseth explained the large plot tillage and residue management trial and the small plot fertility trial that was across the large plots. Nathan Riggers discussed their experiences with direct seed grain legumes in the trial and other fields on their farm. Donn Thill presented the small plot herbicide trials across the large plots and summarized experiences with weed control in direct seed grain legumes at other trial sites. (2) Northern Idaho On-farm testing tour, July 8, 1998 - This tour sponsored by the Nezperce Co. Cooperative Extension included the Keats trial, and was attended by 25 growers and agricultural fieldmen. Roger Veseth and Duncan Cox explained the tillages and experiments on direct seeding for this trial and others in the area. (3) Lewis County Conservation District Tour July 14, 1998 - This tour showed the trial at Eric Hasselstrom's near Winchester, ID. Duncan Cox discussed the tillage treatments, establishment and weed problems in this trial and a general discussion of direct seeding. It was attended by 10 growers and agricultural support personnel. Conferences - The Northwest Direct Seed Intensive Cropping Conference in Pasco, WA on Jan. 7-8, 1998 was sponsored by the PNW STEEP III Extension program and a number of other Ag support companies and groups and attended by nearly 900 PNW growers and Ag support personnel. In addition to specific summaries of this project's research on the program and in the Proceedings, the concept of management systems for direct seed grain legume was highlighted by 11 other Conference speakers. (see Proceedings and Presentations for more details) Veseth, R. Dec. 11,
1997. Reduced Tillage Systems for Grain Legumes. USA Dry Pea and Lentil
Council Grower Division Annual Meeting. Moscow, ID - 310 attended. Guy, S.O. and J.
Hammel. Jan. 7, 1998. Research on Direct Seed Systems for Spring Legume
Production After Spring Cereals. Invited presentation at the Northwest
Direct Seed Intensive Cropping Conference, Pasco, WA -900 attended. Guy, S.O. Dec. 12,
1998. Direct Seeding Legumes and Wheat. Extension Small Grain Update.
Compressed Video Broadcast to three location in Idaho. Guy, S.O. Feb. 26,
1999. Direct Seeding Cropping Systems in Northern Idaho - Now and in the
Future. Boundary Co. Cereal School, Bonners Ferry, ID. Guy, S.O. June 16,
1999. Direct Seeding of Peas - Variety Evaluation and Problems. No-till
farm tour. Genesee, ID. Veseth, R.J. July
8, 1998. Direct Seed Peas - Concepts, Research Results and Future Potential.
30 min. On-farm Testing Tour sponsored by Nez Perce County Cooperative
Extension System, Lewiston, ID - 55 attended. Veseth, R.J. July
14, 1998. Direct Seeding Systems with Grain Legumes. 30 min. Conservation
Field Tour sponsored by Lewis County Conservation District and Cooperative
Extension System. Winchester, ID - 15 attended. Veseth, R.J. Jan.
7, 1999. Grower Direct Seed Pea Trials in Eastern Washington and Northern
Idaho. 25 min. Northwest Direct Seed Cropping Systems Conference. Spokane,
WA - 940 attended. Veseth, R.J. Feb. 8, 1999. Grower Direct Seed Pea Trial Results in Eastern Washington and Northern Idaho. 40 min. University of Idaho Extension Cereal School, Potlatch, ID - 55 attended. Veseth, R.J. Feb.
9, 1999. Grower Direct Seed Pea Trial Results in Eastern Washington and
Northern Idaho. 40 min. University of Idaho Extension Cereal School, Lewiston,
ID - 45 attended. Veseth, R.J. Feb.
10, 1999. Grower Direct Seed Pea Trial Results in Eastern Washington and
Northern Idaho. 40 min. University of Idaho Extension Cereal School, Greencreek,
ID - 115 attended. Veseth, R.J. June
29, 1999. Direct Seed Systems for Grain Legumes. 15 min. University of
Idaho's Plant, Soil and Entomological Sciences Dept. Field Day at UI Parker
Research Farm, Moscow, ID - 130 attended. Veseth, R.J. Oct.
12, 1999. Grower Direct Seed Pea Trials in Eastern Washington and Northern
Washington. 50 min. WSU Crop and Soil Sciences Dept. Graduate Soil Seminar.
Pullman, WA - 40 attended. Veseth, R.J. Feb. 19, 2000. Grower Direct Seed Trials with Peas in Washington and Idaho. Montana Pulse Growers Association Annual Meeting. Billings, MT - 240 attended. |
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