Soil evaporation studies using mini-lysimeters under differently established rice-wheat cropping sequence in Punjab, India

Abstract

Present investigations were carried out in rice-wheat cropping sequence as a whole including the intervening period under divergent establishment methods from 2012-14 at experimental farm of Punjab Agricultural University, Ludhiana, Punjab. Treatments included tillage in wheat viz. zero (ZTW) and conventionally tilled wheat (CTW) - main followed by establishment methods viz. direct seeded rice (DSR) and mechanically transplanted rice (MTR) - sub while tillage in rice viz. puddle (PTR), conventionally tilled (CTR) and zero tilled rice (ZTR) - sub-sub plot. Mini-lysimeters were used for delineating the evaporation trends which found to be fast, low cost, reliable and accurate. During rabi seasons, CTW plots evaporated 15.8 and 3.0% faster respectively, as compared to the ZTW plots. CTW plots during 2012-13 evaporated 7% higher than during 2013-14 while ZTW plots evaporated with almost same pace during both the years. After rabi season during intervening period, ZTW plots evaporated 6.8 and 13.6% faster than the CTW plots during 2012-13 and 2013-14, respectively. During rice seasons, among pure tillage system, zero tilled plots viz. ZTWDSRZT evaporated 21.7 and 22.2% faster than CTWDSRCT plots during rice 2013 and 2014, while coming over to the mixed tillage systems, CTWDSRZT evaporated 36.7 and 18.4% faster than the ZTWDSRCT plots. The results from this and other studies suggest that mulching suppress the evaporation losses which further improves the water use efficiency and finally land productivity of the rice-wheat sequence in the region.