Mulching impact of Jatropha curcas L. leaves on soil fertility and yield of wheat under water stress.

In present studies we have evaluated mulching impact of Jatropha curcas leaves on soil health and yield of two wheat (Triticum aestivum L.) varieties Wadan-2017 (rainfed) and Pirsabak-2013 (irrigated) under imposed water stress. Mulch of Jatropha leaves was spread on the soil surface at the rate of 0, 1, 3 and 5 Mg ha after seed germination of wheat. Water stress was imposed by skipping irrigations for one month at anthesis stage of wheat maintaining 40% soil field capacity. We found a significant decline in soil microbial biomass carbon (30.27%), total nitrogen (22.28%) and organic matter content (21.73%) due to imposed water stress in non-mulch plots. However, mulch application at 5 Mg ha significantly improved soil organic matter (38.18%), total nitrogen (37.75%), phenolics content (16.95 mg gallic acid equivalents/g) and soil microbial biomass carbon (26.66%) as compared to non-mulch control. Soil health indicators like soil carbonates, bicarbonates, electrical conductivity, chloride ions and total dissolved salts were decreased by 5 Mg ha mulch application. We noted a decline in yield indicators like spike weight (14.74%), grain spike (7.02%), grain length (3.79%), grain width (3.16%), 1000 grains weight (6.10%), Awn length (9.21%), straw weight (23.53%) and total grain yield (5.98%) of wheat due to imposed water stress. Reduction in yield traits of wheat due to water stress was higher in Pirsabak-2013 than Wadan-2017. Jatropha leaves mulch application at 5 Mg ha significantly minimized the loss in yield traits of wheat crop caused by water stress. Jatropha curcas leaves mulch application at 5 Mg ha is recommended for the successful establishment of wheat crop under water deficit conditions.