North-East India is known for its complex, diverse, risk-prone, and fragile hilly ecosystem. Natural resources in terms of soil, water, vegetation, and soil organic carbon (SOC) are much degraded. Effects of long-term perennial grasses maintained at a permanent fodder block of the ICAR Research Complex, Meghalaya, on soil quality were examined after 15 cropping cycles. The aims were (i) to ascertain whether perennial grass primarily maintained as fodder source for ruminants could conserve resources and improve soil quality in the hilly ecosystem of North-East India, and (ii) to select a suitable perennial grass to minimise land degradation, restore SOC, and improve the soil quality. Soil samples were collected in 2007–08 (dry season) from plots of 8 perennial grasses [Setaria sphacelata (setaria), Brachieria rosenesis (congosignal), Thysanolaena maxima (broom), Penicum maximum var. Makunia and var. Hamil (guinea), Pennisetum purpureum (napier), Paspalum conjugalum (paspalam), Arachis pintoi (wild groundnut)] and analysed for physical, chemical, and biological properties. A control plot had no grass cover. Hamil and Makunia produced a large amount of green fodder, while Makunia, paspalam, setaria, and congosignal had greatest root biomass. Relative to the control, soil under perennial grasses showed increases of ~30% SOC, 70% mean weight diameter, 20% available soil water, 40% hydraulic conductivity, 63% infiltration rate, and 10% soil microbial biomass carbon. Among grasses, soil under setaria, congosignal, and Makunia had higher values of these attributes than under other species because of better soil binding through an extensive root system. Improvement of soil physical properties and processes under these grasses, coupled with complete ground cover, reduced soil erosion by ~33% and also signified ecological benefits through C-sequestration. Soil quality management in the fragile ecosystem of North-East India should include permanent pastural grasses, particularly, setaria, congosignal, and Makunia.

This study was conducted over 3 years in a salt-affected coastal rainfed lowland ecosystem. Farmers most commonly grow tall rice varieties in the wet season to cope with flash and/or stagnant floods, leading to large amounts of rice residue production. Most of the land remains fallow during the dry season because of increased salinity and scarcity of freshwater for irrigation. The study aims to provide options for increasing cropping intensity through management of crop residues (CR) and soil salinity, conservation of soil moisture, and reduction in production cost. The rice–maize rotation was assessed with rice as the main plot as (1) puddled transplanted rice (PTR) with CR of both rice and maize removed, (2) PTR and 40% CR of both crops retained, (3) dry direct-seeded rice (DSR) with CR of both crops removed, and (4) DSR with 40% CR of both crops retained. Maize in the dry season was supplied with different N levels as sub-plots—control (0 kg N ha⁻¹), 80, 120, and 160 kg N ha⁻¹. DSR, when combined with CR retention (DSR + R), reduced soil salinity. The increase in rice grain yield with CR retention (observed in second and third years) and crop establishment (higher in DSR versus PTR in the third year) was 16 and 24%, respectively. The cost of production increased by 17% (USD 605 ha⁻¹) in PTR compared with DSR (USD 518 ha⁻¹). CR retention reduced irrigation water requirement by 37% and N requirement by 40 kg ha⁻¹ for hybrid maize. When CR was removed (−R), the N requirement for hybrid maize increased to 160 kg N ha⁻¹ compared to when it was partially (40%) retained, where the requirement was 120 kg ha⁻¹ with similar yields. Available N was highest under DSR + R (314 kg ha⁻¹) and lowest under PTR − R (169 kg ha⁻¹), and it also increased with increasing N application up to 120 kg ha⁻¹ (+R) and 160 kg ha⁻¹ (−R). The results of the study hold promise for increasing cropping intensity and farmers’ incomes, with broader implications for increasing productivity on about 2.95 million hectares currently under a rice–fallow system in eastern India, and in coastal areas affected by similar conditions in South and Southeast Asia.

Nano-fertiliser has come up to reduce the use of inorganic fertilisers and to reduce the antagonistic effects of fertilizers on the environment. A field experiment was laid out under the randomised block design (RBD) in coastal West Bengal, India during kharif season of 2022 to examine the efficacy of IFFCO nano-urea in okra (Abelmoschus esculentus) cultivation. The treatments were T₁ = no fertiliser; T₂ = recommended fertiliser dose @ 90:45:45 kg ha^-1:: N:P₂O₅:K₂O; T₃ = 1/3 N urea, PK + 1/3 N urea + 1/3 N nano-urea on equivalent basis (nano); T₄ = 1/3 N urea, PK + 1/3 N nano + 1/3 N nano; T₅ = 1/3 N nano, PK + 1/3 N nano + 1/3 N nano. Nitrogen was applied in three split doses whereas P and K were applied as basal. The plant vigour was recorded 50 days after sowing using Trimble Green Seeker. T₂ and T₃ recorded significantly higher normalised difference vegetation index (NDVI) values, and T₁ recorded the lowest. Maximum okra yield was recorded in T₂ whereas 44.7%, 18.5%, 38.1% and 41.2% yield reductions were recorded in T₁, T₃, T₄, and T₅, respectively. Fruit nitrogen content was also maximum in T₂ (2.31% on a dry weight basis). The nitrate content in leachate was maximum in T₂ (1.22 mg L^-1) as compared to nano urea treated plots (0.74-0.85 mg L^-1). The results of GHG measurement showed that the N₂O emission decreased to 0.79-1.71 mg m^-2 day^-1 with nano-urea in comparison to 2.85 mg m^-2 day^-1 with conventional prilled urea. The field experiment showed that there was a yield penalty in case of nano-urea application but it has environmental benefits in terms of minimum nitrate level in leachate and low N₂O emissions than the conventional urea application.