Effects of non-leguminous cover crops and their times of chopping on the yield and quality of no-till baby corn (Zea mays L.) were evaluated during two kharif seasons (May-August in 2014 and 2015) under subtropical climatic conditions of Punjab, India. The experiment was laid out in a split-plot design with four replications at Punjab Agricultural University’s Research Farm. Three cover crops (pearl millet (Pennisetum glaucum L.), fodder maize (Zea mays L.), and sorghum (Sorghum bicolor L.)) and the control (no cover crop) were in the main plots and chopping time treatments (25, 35, 45 days after planting (DAP)) in the subplots. During both kharif seasons, the yield (cob and fodder yield) and dry matter accumulation of baby corn following cover crop treatments, especially pearl millet, were significantly (p ≤ 0.05) higher than the control, and improved with increments in chopping time from 25 to 45 DAP. The effect of cover crops on baby corn quality (i.e., protein, starch, total soluble solids, crude fiber, total solid, and sugar content) did not differ among treatments, while increasing increments in chopping time had a significant effect on the protein and sugar content of baby corn. The use of cover crops and increment in chopping time helped in enhancing topsoil quality, especially available nitrogen; yet, the effect of cover crops and their times of chopping on topsoil organic carbon, phosphorus, and potassium did not differ among treatments. During both seasons, there was no significant interaction between cover crop and time of chopping among treatments with respect to baby corn yield and quality, as well as topsoil quality parameters.
Mustard (Brassica sp.) seed meal (MSM) and sunflower (Helianthus annuus L.) seed meal (SSM) are the byproducts of the seed oil extraction process. They release biologically active allelochemicals that can provide a resource for supplemental nutrients and weed suppression in vegetable cropping systems. Our field experiment aimed to assess the phytotoxic impact of MSM and SSM on weeds and seedling establishment of direct-seeded pumpkin under semi-arid conditions and to study the impact of MSM and SSM on soil physical properties and soil water retention characteristics. The meals were incorporated into the soil 2 weeks before pumpkin planting at two rates (1150 and 2250 kg ha−1). MSM at both rates reduced early season grass and broadleaf weeds by 75 to 82% and 69 to 76%, respectively, as compared to the untreated control. However, SSM at both rates provided 59 to 65% and 54 to 59% controls of narrow and broadleaf weeds, respectively. Both MSM and SSM provided significantly better weed control and pumpkin yield as compared to the untreated control, but higher pumpkin yield was recorded with a lower rate of MSM. In addition, soils amended by both the seed meals had higher saturated hydraulic conductivity, soil water content, and lower bulk density than the untreated control. Overall, our findings suggest that the use of both MSM and SSM as an organic adjuvant is effective in controlling weeds and improving soil physical properties; however, additional research is required to further evaluate these findings and improve the reliability of MSM and SSM for weed suppression following application to agricultural soils.