Nutrient uptake by weeds and soybean crop as influenced by weed management practices in Vertisols

Abstract

A field experiment was conducted during kharif season of 2021 to study the effect of weed management practices on uptake of nutrients by weed and soybean at Kota (Rajasthan). The results indicated that weeds in soybean depleted the soil fertility by removing 69.2 kg ha-1 N, 12.4 kg ha-1 P and 76.7 kg ha-1 K under unweeded check. All weed management practices reduced weed dry matter and nutrient uptake by weeds at 30 and 60 days after sowing (DAS). Two hand weedings and ready mixture of fomesafen + fluazifop-p-butyl @ 220 g a.i. ha-1 proved significantly superior in reducing weed dry matter and nutrient uptake by weeds at 30 and 60 DAS over rest of the treatments. All weed control measures significantly enhanced seed and straw yield of soybean over weedy check. Two hand weedings and mixture of fomesafen + fluazifop-p-butyl @ 220 g a.i. ha-1 , sodium acifluorfen + clodinafop-propargyl @ 245 g a.i. ha-1 and propaquizafop + imazethapyr @125 g a.i. ha-1 as post emergence (PoE) were at par and were found to be significantly superior over rest of the treatments in enhancing seed and straw yield. Ready mix application of fomesafen + fluazifop-p-butyl @ 220 g a.i. ha-1 , propaquizafop + imazethapyr @ 125 g a.i. ha-1 and sodium acifluorfen + clodinafop-propargyl @ 245 g a.i. ha-1 (PoE) significantly reduced the NPK uptake by total weeds and significantly improved nutrient uptake by soybean and consequently resulted higher seed yields.