Over years of intensive cultivation and imbalanced fertilizer use, the soils of the Indiansubcontinent have become deficient in several nutrients and are impoverished in organic matter.Recently, this region has started emphasizing a shift from inorganic to organic farming to managesoil health. However, owing to the steadily increasing demands for food by the overgrowingpopulations of this region, a complete shift to an organic farming system is not possible. The rice–wheat cropping system (RWCS) is in crisis because of falling or static yields. The nations of thisregion have already recognized this problem and have modified farming systems towardintegrated nutrient management (INM) practices. The INM concept aims to design farmingsystems to ensure sustainability by improving soil health, while securing food for the populationby improving crop productivity. Therefore, this paper was synthesized to quantify the impact androle of INM in improving crop productivity and sustainability of the RWCS in the context of theIndian subcontinent through meta-analysis using 338 paired data during the period of 1989–2016.The meta-analysis of the whole data for rice and wheat showed a positive increase in the grainyield of both crops with the use of INM over inorganic fertilizers only (IORA), organic fertilizersonly (ORA), and control (no fertilizers; CO) treatments. The increase in grain yield was significantat p < 0.05 for rice in INM over ORA and CO treatments. For wheat, the increase in grain yield wassignificant at p < 0.05 in INM over IORA, ORA, and CO treatments. The yield differences in theINM treatment over IORA were 0.05 and 0.13 Mg ha−1, respectively, in rice and wheat crops. Thepercent yield increases in INM treatment over IORA, ORA, and CO treatments were 2.52, 29.2, and90.9, respectively, in loamy soil and 0.60, 24.9, and 93.7, respectively, in clayey soil. The net returnsincreased by 121% (INM vs. CO) in rice, and 9.34% (INM vs. IORA) and 127% (INM vs. CO) inwheat crop. Use of integrated nutrient management had a positive effect on soil properties ascompared to other nutrient management options. Overall, the yield gain and maintenance of soilhealth due to INM practices over other nutrient management practices in RWCS can be a viablenutrient management option in the Indian subcontinent.

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SUMMARYKnowledge of different fractions and availability of boron (B) is essential while studying the response of crops to B. Fractionation provides information about the chemistry of B and quantifies its bioavailability. Such information is potentially valuable for predicting bioavailability, B leaching, dynamics, transformation between chemical forms in soils and environmental impacts. Total B (T-B) is quantified into five fractions: readily soluble (Rs-B), specifically adsorbed (Spa-B), oxide bound (Ox-B), organically bound (Org-B) and residual B (Res-B). Of these, Rs-B is the fraction present in soil solution and adsorbed weakly by soil particles, and is most readily available for plant uptake. It accounts for 1–2% of T-B. The second most plant available form is Spa-B; it may be adsorbed onto clay surfaces or associated with organic matter (OM) in soil. The remaining fractions, Ox-B, Org-B and Res-B, are unavailable for plant uptake. The major portion (generally 87·4–99·7%) of T-B is composed of Res-B. Overall, the relative proportion of B in various fractions is in the order of Res B > Org-B > Spa-B > Rs-B > Ox-B. Several factors such as soil pH, soil OM, clay minerals, iron and aluminium oxides and calcium carbonate content may change the relative proportion of B in various fractions and the transformations among different soil B fractions. Some of the B fractions are correlated with others and exhibit responses in terms of plant growth. Non-specifically adsorbed (Nsa-B) and Spa-B are positively and significantly correlated to some sub-fractions of Ox-B, such as B occluded in manganese oxyhydroxides (Moh-B). The most readily available forms of B for plants are Nsa-B, Spa-B and Moh-B.

This paper examines the quality of groundwater of Sabour block, Bhagalpur district of Bihar state, which lies on the southern region of Indo-Gangetic plains in India. Fifty-nine samples from different sources of water in the block have been collected to determine its suitability for drinking and irrigational purposes. From the samples electrical conductivity (EC), pH and concentrations of

Distribution of boron (B) in different fractions is still not well defined when it is applied in B deficient alkaline calcareous soil and after harvesting of sown crop. In present greenhouse experiment with green gram crop, three B deficient soils with calcium carbonate content 0.8 (S I), 2.1 (S II) and 4.6 (S III) percent were collected from different sites of Ludhiana and Bhatinda districts, Punjab, India. The treatments comprised of five levels of soil applied B 0, 0.5, 0.75, 1.0 and 1.5 mg B kg -1 soil and the experiment was laid out in CRD factorial design with three replications. Mean readily soluble, specifically adsorbed and oxide bound B fractions got increased significantly with increase in B applications. Distribution of readily soluble B was more in low calcareous soil in comparison to high calcareous soil. Mean value of specifically adsorbed, oxide bound, residual and total B were significantly more in high calcareous soils as compared to low calcareous soils. At maturity, specifically adsorbed B converted into other fractions to maintain equilibrium in soil solution. Organically bound B was greater than oxide bound B fraction. Among all fractions, residual fraction accounted of major portion of the total B. Available B was negatively and significantly correlated with calcium carbonate Downloaded by [University of Nebraska, Lincoln] at 14:23 04 April 2015A c c e p t e d M a n u s c r i p t 2 (CaCO 3 ) content of soil (r=-0.99*). At the same time, specifically bound B was also negatively and significantly correlated with readily soluble B (r=-0.99*) while organically bound B was positively correlated with organic carbon content of soil (r=-0.99*).