Rs. Chhokar et al., NUTRIENT REMOVAL BY WEEDS IN SOYBEAN (GLYCINE-MAX) UNDER INTEGRATED WEED MANAGEMENT, Indian Journal of Agronomy, 42(1), 1997, pp. 138-141
An experiment conducted during the rainy season of 1993 and 1994 showe
d that weeds in soybean [Glycine mar (L.) Merr.] depleted the soil fer
tility by removing 53.24 kg N/ha and 9.30 kg P/ha under unweeded check
. Pre-plant application of trifluralin @ 1.0 kg/ha followed by fluazif
op-p-butyl @ 0.75 kg/ha at 20 days after significantly reduced the nit
rogen and phosphorus removal by barnyard grass [Echinochloa colonum (L
.) Link], while trifluralin @ 1.0 kg as pre-plant followed by chlorimu
ron 6.0 g/ha at 20 days proved very effective in decreasing the N and
P removal by quail grass (Celosia argentea L.) and horse purslane (Tri
anthema portulacastrum L.). Pre-plant trifluralin or pre-emergence pen
dimethalin each @ 1.0 kg/ha, followed by 1 hoeing at 35 days resulted
in significant reduction in nutrient removal by weeds and significant
increase in nutrient uptake by soybean and consequently higher grain y
ield.