Alternate Crops for Direct Seeding in the Dryland Inland Northwest
Stephen Guy, UI Crop Management Specialist
Russ Karow, OSU Extension Agronomist
Crops currently grown in the Inland Northwest 1) are adapted to and tolerant of regional climatic conditions; 2) fit grower soil, labor, equipment, and capital resources; 3) fit grower cropping system, financial, and personal goals; 4) have available markets; and 5) have seed, pesticide and other required production inputs available on a cost-effective basis. Each currently grown crop has strengths or weaknesses in each of these areas, but do meet all criteria. Alternate crops must also meet these criteria though seed stocks, registered pesticides, specialized equipment and markets will need to 'grow' as crop acreage increases.
Alternate crops have been evaluated in the Pacific Northwest for nearly 100 years. Soybean, flax, corn, dry beans, oats and other crops were all tested in field trials at the turn of the century. Many alternative crops have been tested to date. While climatic and soil resources have not changed significantly over this time, genetic potential, grower resources, and available markets have. It is useful to again assess the potential for alternate crops in current cropping systems.
Why Alternate Crops?
If current crops are successful, why consider alternatives? If you are thinking you=ll see higher financial return, think again. It is not likely that greater return will be realized from an individual alternate crop per se. But the benefits of alternate crops grown in rotation may increase overall returns, and a diversified cropping system can add income stability. Introduction of a broadleaf crop in an otherwise grass crop system allows control of grassy weeds and disruption of disease cycles. Spring crops in an otherwise winter crop system, or visa versa, allows control of alternate season weeds. Diversification of crops in rotation should reduce acute and chronic disease and insect problems. All crops have different root system structures. Crop rotation allows for plant root exploration and modification of different parts of the soil profile. These changes may reduce the need for production inputs in differing parts of a cropping system and may thereby increase overall profitability.
Crop Sequence Effects on Winter Wheat
In a series of experiments over five years in the 22-25 inch rainfall area of northern Idaho, previous crops were evaluated for crop sequence effects on winter wheat productivity. Dry pea is the most widely grown crop before winter wheat in this area and winter wheat yields following the previous crops are presented as a percentage of winter wheat yield following dry pea (Table 1). These experiments were part of a three year rotation with spring barley the rotation crop before the experimental crops were planted. Therefore, these results show the differences in a 'good' rotation sequence and if these rotational crops were inserted into a continuous cereal system, the response of the following winter wheat should be even greater. Winter wheat grain quality factors were also improved as yield increased.
Table 1. Winter Wheat Yield Following Rotational Crops as a Percentage of the Yield Following Pea, Moscow and Genesee, Idaho
|Previous crop||W. wheat yield as % after pea||# of tests|
|Dry Pea||100 (106 bu/A)||4|
These results show that second year winter wheat is 24% less productive than following a pea crop. Other spring cereal crops appear better for a following winter wheat crop, but are more than 15% poorer than following pea. All the broadleaf crops in these studies gave nearly the same benefit as following pea (96 to 99 %). These comparisons are at a recommended N fertility level for the winter wheat and at high N fertility rates, the differences are somewhat smaller relative to pea. These trials only investigated some alternative crops, but most are feasible for the area. When evaluating the potential return of alternative rotation crops, the crop value should also include the rotation value for following crops.
Potential Alternate Crops
Potential alternate field crops for the Inland Northwest are shown in the accompanying Table 2. Ratings are Abest guesses@ of the authors based on local research, personal experience, or literature review. Ratings are for 1997-98. Pesticide, market and genetic resource availability will change with time. Crops are arranged by growing season and plant type.
Many of the potential alternative crops listed may appear to be standard crops in your cropping area. However, they appear on the list because they are not standard in other areas. This makes them very good candidates to be tried because markets, production knowledge, and crop support inputs are available. It would be prohibitive to give detailed information about each alternative crop listed. More detailed information is available through your Cooperative Extension Service. When considering an alternative crop new to you and especially new to your area, go slowly. Do not risk too many resources in the evaluation. Also remember that an alternate crop many look very promising one year due to growing conditions, but may fail in another year when conditions are different. There can be many pitfalls for alternative crops in adaptability, pest problems, seed availability and marketing. However, the potential for alternative crops to enhance our rotations and provide diversified income should be strong incentives to 'invest' in developing alternative crops for your cropping system.
Table 2. Potential Alternate Crops for the Inland Northwest. (1=definitely not, 3=possibly, 5=definitely)
|Warm-season, Summer grasses|
|Warm-season, summer broadleafs|