Effects of Water Conservation and Stress Mitigation Measures on Water Use Crop Performance and Quality of Rainfed Sunflower Pigeonpea and Rabi Sunflower in Vertisols

Abstract

In rainfed semi-arid tropics, availability of soil moisture during crop period especially at critical stages is most crucial and, therefore, soil and water conservation measures and drought mitigation compounds spray assume significance in successful sunflower production. Field experiments were conducted with an objective to know the effect of water conservation and stress mitigation measures in intercropping involving sunflower and pigeonpea and rainfed rabi sunflower on performance, water use and seed quality. Trials were conducted during Kharif and rabi, 2020-21 and 2021-22 in deep Vertisols at Raichur, Karnataka. Experiment in Kharif was on effect of in-situ moisture conservation practices in sunflower and pigeonpea intercropping. It was laid out in split- plot with three replications. Treatments consist of moisture conservation practices as main plots and cropping system as sub plots. Another experiment was laid out in RCBD on drought mitigation compounds effect on rainfed rabi sunflower. Treatments consists of seed priming by either CaCl2 at 2 % or KH2PO4 at 2 % along with foliar spray of urea at 1%, KNO3 at1%, 19:19:19 at1% and UASR nutri-mixture at 8 g/l at 45 DAS. The results indicated that pre-sowing land configuration of ridges and furrows produced higher sunflower (62.8%) and pigeonpea grain yields (107.3%) over flatbed sowing, besides higher sunflower equivalent yield (SEY-2252 kg ha-1), rainfall use efficiency (3.98 kg ha-mm-1) and water use efficiency (5.06 kg ha-mm-1). It also results greater net returns and BC ratio. However, due to the additional yield by sunflower + pigeonpea (1:1) on ridge and furrow obtained significantly higher SEY (2257 kg ha-1), pigeonpea equivalent yield (2392 kg ha-1), land equivalent ratio (1.54), output energy and economic returns. In rabi experiment seed primed with CaCl2 at 2 % followed by UASR nutri-mixture at 8 g/l at 45 DAS recorded greater seed yield (63.4%) net returns and BC ratio (2.85) over the rest of treatment combinations. Yield improvement in above treatment was