Pre-Sowing Irrigation Plus Surface Fertilization Improves Morpho-Physiological Traits and Sustaining Water-Nitrogen Productivity of Cotton

The changing climatic conditions are causing erratic rains and frequent episodes of moisture stress; these impose a great challenge to cotton productivity by negatively affecting plant physiological, biochemical and molecular processes. This situation requires an efficient management of water-nutrient to achieve optimal crop production. Wise use of water-nutrient in cotton production and improved water use-efficiency may help to produce more crop per drop. We hypothesized that the application of nitrogen into deep soil layers can improve water-nitrogen productivity by promoting root growth and functional attributes of cotton crop. To test this hypothesis, a two-year pot experiment under field conditions was conducted to explore the effects of two irrigation levels (i.e., pre-sowing irrigation (W80) and no pre-sowing irrigation (W0)) combined with different fertilization methods (i.e., surface application (F10) and deep application (F30)) on soil water content, soil available nitrogen, roots morpho-physiological attributes, dry mass and water-nitrogen productivity of cotton. W80 treatment increased root length by 3.1%–17.5% in the 0–40 cm soil layer compared with W0. W80 had 11.3%–52.9% higher root nitrate reductase activity in the 10–30 cm soil layer and 18.8%–67.9% in the 60–80 cm soil layer compared with W0. The W80F10 resulted in 4.3%–44.1% greater root nitrate reductase activity compared with other treatments in the 0–30 cm soil layer at 54–84 days after emergence. Water-nitrogen productivity was positively associated with dry mass, water consumption, root length and root nitrate reductase activity. Our data highlighted that pre-sowing irrigation coupled with basal surface fertilization is a promising option in terms of improved cotton root growth. Functioning in the surface soil profile led to a higher reproductive organ biomass production and water-nitrogen productivity.

Effect of irrigation scheduling and nitrogen levels on growth, yield and water productivity of linseed (Linum usitatissimum L.) under Vertisols

A field experiment was conducted during Rabi season of 2015-16 at the Instructional cum Research Farm, IGKV, Raipur to study the effect of different irrigation scheduling and nitrogen levels on growth, yield attributes, yield, water and nitrogen productivity of linseed (Linum usitatissimumL.). The experiment was laid out in split plot design keeping four irrigation schedules viz., come-up (I1), one (I2), two (I3) and three irrigation (I4) in main plots and four levels of nitrogen viz., control (N0), 30 kg (N1), 60 kg (N2) and 90 kg N ha-1 (N3) in sub plots with three replications. Results revealed that highest seed yield was obtained with linseed provided two irrigations (1683 kg ha-1) and application of 90 kg N ha-1 (1604 kg ha-1). Moreover, crop supplied with two irrigations in combination with 90 kg N ha-1 (I3×N3) gave significantly (P=0.05) highest seed yield (2097 kg ha-1) compared to rest of the treatment combinations. The excessive use of irrigation and fertilizers also affects farmer’s economy, as the crop is relatively low yielder. Two irrigations are better than three irrigations in terms of seed yield and water productivity; and application of 60 kg N is better than 90 kg N ha-1 in view of nitrogen productivity. The WP and IWP were decreasing as increasing the number of irrigation, but increasing with increasing the levels of nitrogen, while NP was highest with two irrigations (11.09 kg, kg-1 N) and application of 60 kg N ha-1 (8.90 kg, kg-1 N).