Vol. 8, Issue 5 (2020)
Trade-off with different establishment methods in terms of irrigation water requirement and weed pressure of rice (Oryza sativa L.)
Author(s): Santhosh UN, Desai BK, Satyanarayana Rao, Masthana Reddy BG, Vinay Krishnamurthy, Naik MK and Amaregouda A
Abstract: Rice consumes more water than any other crop, potentially leading to unsustainable water withdrawals in command areas of irrigated rice ecosystem. Rice production in irrigated ecosystem is going through transition due to rising scarcity of land, water and labour. A major adjustment can be expected in the tillage and method of crop establishment. Direct seeding rice (DSR and WSR) has been proposed as one means of achieving these objectives. Therefore a field study was conducted for three seasons on a clay loam soil in Karnataka, India, during Kharif Season (2015 and 2016), Rabi season (2015) to investigate the trade-off with different establishment methods in terms of crop performance, water saving and weed pressure of rice (Oryza sativa L.). The experiment was conducted in Split-split plot design comprising two tillage practices in main plots, two establishment methods in sub plots and three irrigation scheduling practices in sub-sub plots. Tillage treatments were Dry (No puddling) and wet tillage (puddling), Establishment methods were Direct seeding (DSR, WSR) and Transplanting (NPTR, PTR), Irrigation treatments were based on soil water tension (SWT) ranging from continuous flooding/saturation (daily irrigation) to alternate wetting and drying (AWD) with irrigation thresholds of 10 and 40 kPa at 18-20cm soil depth. Rainfall was average and well distributed in 2014 (763.80 mm), and less than average and well distributed in 2015 (384.60).
Pooled three seasons results indicated that with methods of establishment practices, direct seeding crop matures earlier in 115 days in comparison with transplanted delayed crop maturity by 13 d. direct seeding was more affected than transplanting and more so in the drier year. Crop performance in terms of tiller density, leaf area index and growth rate and yield components were also similar in both establishment methods when irrigation was scheduled daily or at 10 kPa, but crop growth and yield parameters were significantly lower at 40 kPa in both direct seeding and transplanting establishment methods.
In each individual season, yield of direct seeding and transplanting were similar when irrigation was scheduled daily or at 10 kPa. Yields of both direct seeding and transplanting declined under higher water deficit stress (40 kPa irrigation threshold), but more so in direct seeding, and more so in drier year. There was a very large and significant decline in irrigation water input with irrigation at 10 kPa compared to daily irrigation in both establishment methods, but only a very small decline in irrigation amount when the threshold was increased from 10 to 40 kPa. Irrigation water use in direct seeding treatments was significantly lower than in respective transplanting treatments (32% water saving in direct seeding compared to transplanting).
The results suggest the feasibility of reducing irrigation amount while maintaining yield by replacing transplanting with DSR with AWD during wet season and WSR with AWD during dry season, provided that soil tension is kept lower than 10 kPa at 20cm depth, but that threshold needs to be tested over wider range of site conditions and varieties.
DOI: 10.22271/chemi.2020.v8.i5o.10437
Pages: 1060-1068 | 700 Views 173 Downloads
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How to cite this article:
Santhosh UN, Desai BK, Satyanarayana Rao, Masthana Reddy BG, Vinay Krishnamurthy, Naik MK, Amaregouda A. Trade-off with different establishment methods in terms of irrigation water requirement and weed pressure of rice (Oryza sativa L.). Int J Chem Stud 2020;8(5):1060-1068. DOI: 10.22271/chemi.2020.v8.i5o.10437
