Effects of methods and systems of the primary soil tillage on the yields of seed, vegetable oil and protein of soybean and spring rapeseed in the first crop rotation cycle

We studied the influence of various methods and systems of the primary soil tillage on the yields of seeds, vegetable oil and protein of soybean and spring rapeseed at the All-Russian Rapeseed Research Institute (Lipetsk, Lipetsk region) in 2015–2018. In the field crop rotation (soybeans, winter wheat, spring rapeseed and barley), four systems of the primary soil tillage have been carried out, these are conventionally referred to as: moldboard-surface tillage, moldboardsurface tillage with deep loosening, moldboardsurface tillage with shallow loosening and minimal treatment (subsurface). The soil at the experimental field was leached, heavy clay loam chernozem. The weather conditions during the vegetative period varied according to the years of the research, which affected the seed yield and quality of soybean and spring rapeseed. We revealed the largest and relatively equal yields of seeds, vegetable oil and protein per a hectare of soybean and spring rapeseed was provided by moldboard-surface tillage (plowing under soybean and rapeseed, surface tillage for winter wheat and barley) and moldboard-surface tillage with deep loosening (deep subsurface loosening under soybean, plowing under spring rapeseed and surface tillage under winter wheat and barley), and the lowest yield was obtained using minimal soil treatment (chisel plowing under spring rapeseed and surface tillage under soybean and cereal crops). The quality of seed yield of oil crops in the studied experimental variants was practically equal. At the same time, in general, during the experimental period, the yield and the total yields of vegetable oil and protein of spring rapeseed were significantly higher than those of soybean.