English

Abstract

Challenge of increasing food production in the next 20 years to match population growth is daunting and warrants improvement in the quality of natural resources for growing more food from marginal and degraded lands.Adopting a better tillage system does not only improve the soil health and crop productivity but also improves the environment. A field experiment was conducted to investigate the effects of tillage and irrigation management on wheat (Triticum aestivum L.) production in a post-rice (Oryza sativa L.) management system on sandy loam soil for 2009 to 2010 and 2011 to 2012. Four irrigation levels (I1:irrigation at crown root initiation (CRI); I2:irrigation at CRI+jointing; I3:irrigation at CRI+ jointing+ flowering; I4:irrigation at CRI+ jointing+flowering+dough) stages and three tillage systems (ZT: zero tillage;BPW:bed planted wheat and CT:conventional tillage) were tested. Zero tillage compared to CT, resulted in higher bulk density (1.60 vs 1.49 Mg·m-3), lower total porosity (49.3 vs 53.7%), higher penetration resistance (1.50 vs 1.24 MPa), and lower steady state infiltration rate (0.18 vs 0.38 mm·h-1)  in the surface 0 to 15 cm soil layer.Irrigation levels significantly affected crop water use, wheat yield, and water use efficiency (WUE). Aggregates<25 mm ZT was significantly higher (4.4%), than CT and BPW methods (3.2 and 3.4%, respectively. Grain yield declined by 20.5, 11.7 and 7.7% of I4 (4.57 Mg·ha-1) with I1,I2 and I3 treatments. Average values of WUE were 17.40, 15.97 kg·ha-1·mm-1and 14.88 m3·kg-1grain for the BPW, ZT and CT treatments and water storage efficiency were 21.9, 24.5 and 29.2%, for CT, ZT and BPW, respectively.   Key words: Conventional tillage, soil physical properties, water balance, water retention, zero tillage.