Soil residual water and nutrients explain about 30% of the rotational effect in 4-year pulse-intensified rotation systems

Diverse crop rotations enable the best use of residual soil water and nutrients, thus, decreasing production inputs. Here, we determined the effect of cropping sequences on soil residual water and nutrients, and the performance of subsequent wheat (Triticum aestivum L.). Nine rotation systems were evaluated at Swift Current, Saskatchewan, and Brooks, Alberta, from 2010 to 2014. Pea (P) (Pisum sativum L.) and lentil (L) (Lens culinaris Medik.) as preceding crops before wheat (W) or the rotation systems with pea (PPPW) or lentil (LLLW) included more than once in the 4-yr rotations had the highest residual soil water and N in the 30-90 cm depths, and continuous wheat (WWWW) had the lowest. Preceding pea and lentil increased the grain yield of the subsequent wheat by 26% and 18%, respectively, as compared with the continuous wheat. Variance partitioning of redundancy analysis revealed that soil residual water and residual N explained 12.4 to 42.7% (average 30%) of the yield variation observed in the subsequent wheat, with the rest of the rotational benefits unexplainable by soil residual water and residual nutrients. Investigation of the factors other than soil water and nutrients that contribute to the succeeding wheat yield may further enhance the rotational effect.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author