Agriculture Reference
In-Depth Information
Such large yield gaps (Table 5.1) have also been highlighted in other studies
(Aggarwal and Kalra 1994; Aggarwal et al. 2000; Pathak et al. 2003; Saharawat
2009). In an integrated analysis of the long-term trials carried out across 23 Indo-
Gangetic plain sites, Tirol-Padre and Ladha (2006) reported that wheat yields had
not improved even after 7-23 years, while surprisingly rice yields had declined dur-
ing the same periods. Despite geographical proximity, the productivity of rice in
Bihar is much lower than in those in Nepal and Bangladesh. Late planting, uncon-
trolled water supplies, monsoon floods, and lack of supplemental irrigation facilities
and less fertilizer use are some of the reasons for the low productivity of rice in
Bihar. Many of these reasons are surmountable. Boro rice (cultivar Gautam), seeded
during receding winter and transplanted in early February in Bihar, West Bengal,
and Bangladesh usually yield double than aman (monsoon) rice. A cropping sys-
tem comprising winter maize (
Zea mays
L.) and boro rice can thus contribute to a
significant jump in agricultural productivity in the eastern Gangetic plains of Uttar
Pradesh, Bihar, West Bengal, and Terai of Nepal and Bangladesh. This requires fur-
ther research efforts and shifts in rice production technologies, including the use
of modern cultivars, water-efficient technologies like precision leveling, direct dry
seeding, intermittent irrigation, and weed and nutrient management. The produc-
tivity of scented Basmati cultures is often lower than that of improved nonscented
rice. Haryana and Pakistan Punjab farmers grow more Basmati rice than farmers in
Indian Punjab. It is for this reason that the rice yield gaps apparently look more in
Haryana than in Punjab.
In case of maize, the management yield gaps are more glaring in kharif maize
with productivity being comparatively very low in Bihar and West Bengal than in
Bangladesh with similar kinds of environments. Lesser adoption of high-yielding
single-cross hybrids along with higher yield losses due to biotic and abiotic stresses
often results in poor yield realization at the farmers' field in these areas. The produc-
tivity of kharif maize is also very low in Punjab, largely because of its restriction to
marginal rainfed environments. On the other hand, spring maize after potato, grown
with assured irrigation and input supply, gives a very high yield. The development
and adoption of waterlogging-tolerant single-cross maize hybrids during the kharif
season, or alternatively, the introduction of short-duration rice-potato-winter maize
or rice-mustard (
Brassica juncea
)-mung bean (
Vigna radiata
, R. Wilczek) crop-
ping systems along with some groundwater development can provide a much-needed
impetus to better yield realization in the eastern Gangetic plains.
Management yield gaps are comparatively very low in northwestern Gangetic
plains in comparison with those of the eastern Gangetic plains. Late planting and
consequently terminal heat stress have been identified as the biggest reasons for poor
yield realization in wheat in the simulation studies reported earlier. The daily losses
due to late planting of wheat in the northeastern plains are 60 kg/ha, against 26-32 kg/
ha in the northwestern plains (Aggarwal and Kalra 1994; Ortiz-Monasterio et al.
1994; Dhillon et al. 2000; Mehla et al. 2000; Ortiz et al. 2008; Rajaram et al. 2008;
Timsina et al. 2008). Late harvesting of rice, delay wheat seeding, and these coupled
with lower application of fertilizers and inadequate water supplies result in very large
yield gaps (about 50%) in the northeastern plain zone. On the other hand, the issues
for management yield gap (20%) in the northwestern plains of India—deteriorating
