Studies on Micro-Irrigation in Reduced and Zerotill Direct Seeded Rice (Oryza Sativa L.) in Rice Wheat Cropping System

Abstract

In India rice (Oryza sativa L.) contributes nearly> 40% to words food grain with nearly 43 m ha and is staple food for 65% of the population. Rice-wheat predominant. Signs of fatige in Rice-Wheat, predominant rice based cropping system, are however for the researchers attributed to multifarious problem like productivity stagnation, declining factor productivity, narrowing profit margins, natural resource degradation, environmental pollution etc. A field experiment was, therefore, conducted to address the issue on loam soil, low in organic carbon & nitrogen and high in available phos~horus and potassium at SVPUAT, Meerut, located in semi-arid and sub-tropical region at 29 13' 96" N latitude, 77° 68' 43" E longitudes and at an elevation of 218 meters above the MSL, during 2010 and 2011 . Treatment (11) comprising combinations of irrigation techniques (05- Flood, drip, chapin, sprinkler and LEWA) in main-plot and tillage (02- Reduced and Zero) in sub-plot direct Seeded Rice (DSR) alongwith Conventional Puddled Transplanted Rice (PTR) were tested in split plot design with 3 replications. Result revealed that PTR gave 5.2% higher yield (51 .85 q ha·\ fetched net returns of Rs. 15116 ha·1 with B:C ratio 1.33 in comparison to DSR (49.2 q ha'\ Rs. 15108 ha'1 & 1.35,respectively) owing to batter growth i.e. total tillers (343 m·2 ) and dry matter accumulation (974.9 g m·2 ) and yield attribute viz effective tillers (207 m'2 ), panicle length (26 em), and grain per panicle (231). However DSR had higher water productivity (6.25 kg grain mm·1 water) with 24% water saving. Residual soil fertility and physical properties were also favorable under DSR. Amongst irrigation systems the crop gave highest yield with sprinkler system (50.7 q ha-1 ) and fetched 3.5% more returns (Rs 16252 ha-1 ) with B:C ratio (1.38) accounted to better early establishment of crop (Total tillers, dry matter accumulation) and subsequent synthesis of various yield attributes (fertile tillers 205.5, panicle length 25.5 em and grain per panicles 222). In general micro-irrigation systems had higher water productivity with water saving (31.8%Sprinkler, 45.6%- Drip, 45.6%- Chapin & 24.5%- LEWA) and favorable residual soil fertility and physical tillage. DSR with reduced tillage gave higher yield (51 .1 q ha'1 ), higher returns (Rs. 59802 ha· \ more water productivity (6.39 kg grain mm·1 water) and favorable residual availability of nutrient in comparison to zero tillage. Dry matter accumulation (961 g m'2 ), total tillers (306), effective tillers (205), grains per panicle (214) and panicle length (25 em) were also higher with reduced tillage. Thus, it can be inferred that PTR is the good option under assured and sufficient irrigation and rainfall conditions. Further, DSR with reduced tillage can go a long way in economizing water use if raised with suitable system of irrigation. Sprinkler irrigation system ~nstalled at a spacing of 4 x 4 meter with discharge of 140 liter nozzle'1 and operated at 4 days Interval, based on crop ET demand, was most efficient in realizing high yield. Water and nutrient losses were also reduced sprinkler irrigation which increased input use efficiency. DSR with sprinkler irrigation saved 31% over flood irrigation, and 46% against PTR.