Conservation agriculture and weed control effects on productivity and resource-use efficiency in rice-wheat cropping system
Loading...
Date
2017
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
DIVISION OF AGRONOMY ICAR-INDIAN AGRICULTURAL RESEARCH INSTITUTE NEW DELHI
Abstract
Conservation agriculture (CA)-based rice (Oryza sativa L.) - wheat (Triticum
aestivum L. emend Fiori&Paol.) cropping system (RWCS) can be the possible option for
higher productivity and sustainability of the RWCS in the North-western Indo-Gangetic
plains of India. But, weed infestation is the most important constraint towards its adoption.
The CA influences weed species dynamics and competition in RWCS and affects the
productivity of crops. A suitable integration of CA and weed management option can lead to a
viable and sustainable RWCS through effective weed management that leads to higher
productivity and resource-use efficiency. Therefore, field experiments were carried out at the
ICAR-Indian Agricultural Research Institute, New Delhi during 2012-13 and 2013-14 to find
out best weed control option for reducing crop-weed competition in RWCS, and to evaluate
the effects of CA and weed control measures on resource-use efficiency, crop productivity
and economics. The experiment was laid out in a split plot design, keeping CA practices in
main plots and weed control measures in sub-plot with three replications. The CA treatments
were: direct-seeded rice (DSR) - zero till wheat (ZTW), DSR - ZTW + rice residue retentions
(RR), DSR + BM (brown manuring) - ZTW, DSR + BM - ZTW + RR, Mungbean residue
(MR) + DSR – ZTW - zero till summer mungbean (ZTSMB), MR + DSR – ZTW + RR –
ZTSMB + wheat residue retentions (WR), transplanted puddled rice (TPR) - ZTW and TPR –
conventional till wheat (CTW). Weed control treatments in rice comprised of unweeded
control (UWC), pre-emergence applications of pendimethalin at 1.5 kg/ha followed by postemergence
applications of bispyribac-Na at 25 g/ha at 25 DAS/DAT, and these combination
also integrated with one hand weeding (HW); and in wheat: unweeded control (UWC), preemergence
application of pendimethalin at 1.0 kg/ha applied alone at 2 DAS; and
sequenctional applications of pre-emergence pendimethalin at 1.0 kg/ha alone at 2 DAS
followed by post-emergence applications of sulfosulfuron at 25 g/ha at 30 DAS.
CA practices like brown manuring, summer mungbean and rice residue retention
and zero till wheat influenced the growth, yield and yield attributers of rice and succeeding
wheat. Higher rice yield was recorded in TPR than DSR practice. Among DSR practices, the
triple cropping system including a legume (i.e. mungbean), MR + DSR – ZTW + RR –
ZTSMB + WR combined with sequenctional applications pendimethalin followed bispyribac
supplemented with one HW was found best treatment. It was next to TPR practices (TPR -
ZTW & TPR - CTW) on the growth, yield, and yield attributes of rice. On the contrary, ZTW
performed better than CTW. Higher growth and yield of wheat were recorded in ZTW. In
wheat, the MR + DSR – ZTW + RR – ZTSMB + WR (with residues of three crops) and MR
+ DSR – ZTW– ZTSMB (without residue) and the applications of pendimethalin fb
sulfosulfuron resulted in higher values of growth parameters, yield and yield attributes
compared to the TPR - ZTW and TPR - CTW systems. The overall system productivity and
monetary benefit were higher with treatments, MR + DSR – ZTW + RR –ZTSMB +WR
combined with pendimethalin fb bispyribac along with one HW in rice, and pendimethalin fb
sulfosulfuron in wheat.
DSR was infested with diverse weeds in large numbers than TPR. Grassy weeds
were more dominant than others in rice. Among DSR practices, the DSR - ZTW and DSRZTW
+ RR had maximum weed infestation. In wheat, broad-leaved weeds were more
dominant, and higher weed infestation was observed in conventional till wheat practices, i.e.,
TPR-CTW and TPR-ZTW. The applications of pendimethalin fb bispyribac along with one
HW in rice and pendimethalin fb sulfosulfuron in wheat effectively controlled weeds and
provided higher weed control efficiency (WCE). The populations of plant-parasitic
nematodeswere higher in DSR and ZTW practices than conventional practices. Treatments,
DSR + BM - ZTW and DSR + BM – ZTW + RR resulted in higher number of nematodes in
both rice and wheat. Weed density and nematode population were positively correlated.
Herbicide application significantly reduced nematodes population. Higher values of microbial
biomass carbon (MBC) and soil dehydrogenase activity (DHA) were associated with DSR
and ZTW practices. Weed control measures did not affect microbial activity. CA practices
had significant impacts on C pools, available NPK and soil organic carbon. The
treatments,MR + DSR – ZTW + RR – ZTSMB + WR, MR + DSR – ZTW – ZTSMB, and
DSR + BM - ZTW + RR resulted in higher very labile C and available NPK. Weed control
measure did not influence C pools and soil organic carbon.
Thus, based on the two-year studies, a combination of the CA-based triple cropping
system that involves summer mungbean residue retention in direct-seeded rice, followed by
zero till wheat with rice residue, and zero-till summer mungbean with wheat residue retention,
and the applications of pre-emergence pendimethalin 1.5 kg/ha alone followed by postemergence
bispyribac-Na 25 g/ha at 25 DAS/DAT supplemented with one 1 hand weeding in
rice, and the applications of pre-emergence pendimethalin 1.0 kg/ha at 2 DAS alone followed
by post-emergence applications of sulfosulfuron 25 g/ha at 30 DAS in wheat, may be
recommended for better weed management and higher crop productivity, profitability and
resource-use efficiency in the North-western Indo-Gangetic Plains of India.
Description
t9606
Keywords
null