Pulse crops for the northern Great Plains: II. Cropping sequence effects on cereal, oilseed, and pulse crops

To optimize cropping system benefits from pulse crops, it is important to understand their effects on subsequent crops. The objective of this study was to compare the effects of chickpea (Cicer arietinum L.), lentil (Lens culinaris Medik.), and pea (Pisum sativum L.) stubbles on yield and quality of wheat (Triticum aestivum L.), mustard (Brassica juncea L.) or canola (B. napus L.), and lentil or pea when grown on soils with clay and loam textures. This study was conducted between 1996 and 1999 in southwestern Saskatchewan. Rotational benefits of pulse crops (chickpea, lentil, and pea) to wheat appeared more consistent on the clay than the silt loam soil. Adjusting fertilizer N rates to account for estimated total N contribution from the previous pulse crop effectively neutralized the benefits on wheat yield and protein compared with the effects following mustard. Canola or mustard productivity was occasionally greater when grown on pea or lentil stubbles compared with mustard and wheat stubbles. The yield increase was attributed to increased available water. Under drier-than-normal conditions, pea yields were highest when grown on wheat stubble. Wheat productivity was least when grown on its own stubble. Pea and lentil provided rotational benefits to wheat, mustard, and canola and benefitted most from being grown in wheat stubble, indicating a strong fit for diversified cropping systems on the semiarid northern Great Plains.