Trial Report Summary

WADO

1. Determine yield obtained from soybean and flax intercropped in paired rows
2. Determine the precision spread of urea on soybean yield and nodulation with and without
agrotain inhibitors
3. Determine the effects of fertilizer and crop type (interaction) in soybean-flax intercrop on yield
and nodulation

Intercropping is an agricultural system that has been embraced worldwide as a result of its benefits that include: greater yields, less diseases, insect pests and weed pressure, soil and moisture conservation and improving soil nutrient status without the need for more synthetic fertilizers than in sole cropping systems (Szumigalski and Van Acker, 2005). Although there might be challenges in harvesting mixed crops, there has been an increase in acres under intercropping in Western Canada as a result of benefits associated with it. Any intercropping system involving soybean usually results in nitrogen credits for the succeeding crop and this in turn results in reduction in fertilizer costs and higher gross returns. Most intercropping systems involve a legume and non-legume crop so as to maximize symbiotic benefits from both crops. In most cases, legume-cereal intercrops result in increased dry matter production and grain yield more than sole crops. When there is a limitation in fertilizer nitrogen, biological nitrogen
fixation becomes the major source of nitrogen in mixed cropping systems involving a legume crop (Fujita et al., 1992). The use of legumes that are tolerant to nitrate and whose biological nitrogen fixation is less affected by application of combined nitrogen, may increase the amount of N available for the other component crop without affecting nodulation of the legume itself. When applying nitrogen to legumes, it is important to consider factors such as the source, rate, timing and placement depth, termed the 4R strategy for successful management of nutrients. Research conducted by Takahashi et al. (2012) suggested that deep placement of coated urea at seeding did not depress nodulation resulting in improved soybean growth and increase in seed yield while top dressing with the same fertilizer inhibited nodule activity after R3 stage, and subsequently resulted in low seed yield. In a related study by Laboski (2006), Agrotain was shown to effectively reduce the conversion of surface applied urea or urea ammonium nitrate to ammonium resulting in increased grain yield due to reduced nitrogen losses. This study therefore seeks to determine the influence of soybean and flax intercrop and whether agrotain
inhibitor has any influence on nodulation and seed yield between the component crops.

Entire findings are available by downloading the report PDF.

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