Effect of tillage and weed control on weed dynamics, crop productivity and energy-use efficiency in rice (Oryza sativa)-based cropping systems in Vertisols

Abstract

Field experiments were conducted during winters of 2004–06 on a Typic Chromusterts soils at Jabalpur to study the effect of tillage and weed control on weed dynamics, productivity and energy-use efficiency of various oilseeds and pulses grown in rice (Oryza sativa L.)-based systems. Results revealed that zero tillage significantly increased the population of common vetch (Vicia sativa L.) but reduced the problem of common lambsquarters (Chenopodium album L.) compared with the conventional tillage. The suppressing effect of crops on total weed dry matter was in order of pea (Pisum sativum L.) > linseed (Linum usitatissimum L.) > mustard (Brassica juncea Czernj & Cosson) > chickpea (Cicer arietinum L.) > lentil (Lens culinaris Medik.). Pre-emergence application of pendimethalin 1.0 kg/ha significantly reduced the dry biomass of all weeds except common vetch (Vicia sativa L.). Higher yields of mustard, lentil and chickpea were recorded under conventional tillage and that of field pea under zero tillage. Field pea proved most economical under zero tillage with net returns of ` 23 199/ha and benefit:cost ratio of 2.87. However, the Indian mustard was more economical under conventional tillage (` 21 039 and 2.31). The maximum energy productivity was obtained under zero tillage in all the crops. The highest output energy (50 675 MJ/ha) and energy output : input ratio (5.02) were obtained from mustard in conventional tillage with pendimethalin.