Impact of conservation tillage practices on the growth and yield of blackgram (Vigna mungo) in rice (Oryza sativa)-blackgram cropping system

Abstract

A field experiment was conducted during post rainy seasons of 2015–16, 2016–17 and 2017–18 (December-March) at research farm of Tamil Nadu Rice Research Institute, Aduthurai, Tamil Nadu to study the impact of tillage practices adopted in the rice (Oryza sativa L.) crop on the succeeding blackgram (Vigna mungo L.) grown as relay cropping. The treatment comprised of 2 tillage practices (puddled and non-puddled), 3 seed priming methods (Bio-seed priming with Rhizobium, hydropriming and no seed priming) and 2 foliar spray (2% DAP and 2% urea). The results indicated though blackgram grown as succeeding crop in the puddled tillage registered higher values of Relative water content (RWC) (83.06 and 83.72%), Specific leaf weight content (SLW) (6.83 and 6.28 g/cm2), Soil Plant AnalysisDevelopment chlorophyll meter values (40.88 and 39.75) at 30 and 45 DAS respectively, it was comparable with non-puddled tillage method. However, the blackgram sown as succeeding crop in non-puddled transplanted rice registered a greater number of nodules (23.67 and 17.44) and nodules dry weight (0.17 and 0.11 g) at 30 and 45 DAS respectively as compared to puddled transplanting. Similarly, the root length (6.93 and 8.62 cm) and root dry weight (0.151 and 0.174 g at 30 and 45 DAS respectively) were also higher with non-puddled tillage. The yield obtained under non-puddled tillage system was 11.8% higher than puddled method of tillage system. Bio-seed priming with rhizobium had higher values of growth and yield parameters, which eventually resulted in 25.0% yield increase over no seed priming. As far as foliar spray concerned, DAP 2% spray and Urea 2% spray did not differ significantly for none of the parameters except for yield.