Soil and Water conservation

A field experiment was conducted during the Kharif season of 2019-2020 and 2020-2021 under acidic soil conditions in Nagaland. The experiment was laid out in randomized block design with 11 treatments and 3 replications. Growth and yield parameters were recorded. The data were analyzed and computed statistically to compare the treatment effect. The plant height, number of branches per plant, yield attributes, seed, stover yield and nutrient uptake are influenced significantly by the combined application of fertilizer, biochar, and pig manure. The highest values of these parameters were recorded with T9 (RDF + 2.0 t ha-1 pig manure + 5.0 t ha-1 wood biochar) treatment. The T9 treatment increased seed yield by 86.3% and 76.1% and stover yield by 30.8% and 30.3%

Twelve treatments involving N, P and K (NPK) fertilizers, farmyard manure (FYM), poultry litter, forest litter, Azospirillum and Zn either alone or in combinations were applied continuously for ten years to evaluate the effect of integrated nutrient management practices on performance of upland rice in a terraced land. The plant height, numbers of tillers and productive tillers increased significantly in all the treatments whereas, grain yield increased significantly in all the treatments except ½N+PK and Forest litter burned+½ FYM over control. Among different nutrient management practices, NPK+Poultry litter produced maximum grain and straw yield. The grain yield in NPK+Poultry litter, NPK+FYM+Zn, NPK+FYM and NPK+Forest litter increased significantly (55.9, 45.7, 37.0 and 29.8%, respectively) as compared to addition of NPK alone. Increase in straw yield in different nutrient management practices ranged from 22.0 to 130.0%. The uptake of N, P and K was significantly higher in treatments where NPK was added with FYM and poultry litter. The average contribution towards apparent recovery of N, P and K from FYM was 36.4, 56.2 and 69.2%; from poultry litter 43.5, 27.7 and 85.9%; and from forest litter 80.4, 98.8 and 44.7%, respectively. After a decade of continuous cultivation, NPK+Poultry litter was found to be the best nutrient management practice that can be adopted for cultivation of upland rice on terraced land followed by NPK+FYM+Zn and NPK+FYM.

The effect of land use on soil physico-chemical properties were studied in four villages, viz., Nongstoin, Kynshi, Umyiap and Maweit in West Khasi Hills district, Meghalaya, under four land uses, viz., paddy, potato, forest and jhum land, in each village. The soils of the study area were acidic in reaction, high in organic carbon and low to medium in cation exchange capacity. Bulk density and particle density were lower in surface soils as compared to sub-surface soils except in some locations. The water holding capacity was greatly influenced by mechanical composition and organic matter content in soils. The mean weight diameter and per cent aggregation showed similar trend and were significantly correlated. Hydraulic conductivity under potato and jhum land uses was higher than paddy and forest land uses.

The effect of land use on soil erodibility parameters were studied in four villages, viz., Nongstoin, Kynshi, Umyiap and Maweit in West Khasi Hills district, Meghalaya, under four land uses, viz., lowland paddy, potato, forest and Jhum land, in each village. The textural class of the soils varied from silt loam to clay with dominance of clay loam texture. Dispersion ratio and erosion index were recorded to be usually higher than the threshold limits. A highly significant and negative relationship of erosion index with clay, silt + clay and highly significant and positive relationship with sand and dispersion ratio were observed. The increase in erosion index with increase in dispersion ratio indicated the susceptibility of these soils to water erosion. Proper soil and water conservation measures need to be adopted to protect the soils from further degradation.

A long-term field experiment was started in 2001 on newly constructed bench terraces at the Department of Soil and Water Conservation in the experimental farm of School of Agricultural Science and Rural Development (SASRD), Nagaland University (NU), Medziphema, Nagaland to study the long term effects of various nutrients management practices on performance of upland rice and fertility of terraced land under rainfed condition. Twelve treatments involving N, P and K (NPK) fertilizers, farmyard manure (FYM), poultry litter, forest litter, Azospirillum and Zn either alone or in combinations were applied continuously for twelve years to evaluate the effect of integrated nutrient management practices on available N, P and K content and performance of upland rice in a terraced land. The available N and K content increased significantly in all the treatments whereas, available P content increased significantly in all the treatments except Forest litter burned+ ½ FYM over control. The highest accumulation of available N, P and K was found in NPK+ Poultry litter, NPK+ FYM and ½N+ PK+ ½N Forest litter treatments, respectively. The rate of build up of available N, P and K in different nutrient management practices varied from 3.57 to 22.5, 0.19 to 1.09 and 3.35 to 13.3 kg ha-1 yr-1 , respectively. Maximum plant height was recorded in NPK+ FYM+ Zn treatment. The number of productive tillers per plant was also highest in NPK+ FYM+ Zn treatment. The highest straw yield was recorded in NPK+ FYM followed by NPK+ Poultry litter treatment. The highest grain yield was recorded in NPK+ FYM+ Zn followed by NPK+ Poultry litter treatment. Compared with NPK, grain yield in NPK+ FYM+ Zn, NPK+ Poultry litter and NPK+ FYM treatments increased significantly and were 38.1, 34.43 and 32.6 per cent higher, respectively. Among different nutrient management practices, NPK+ FYM+ Zn proved to be the best practices followed by NPK+ Poultry litter and can suitably be recommended for use not only to build up available N, P and K levels but also to produce higher grain yield in terraced land under upland rice cultivation.

An experiment was conducted in the experimental farm at School of Agricultural Sciences and Rural Development, Medziphema, Nagaland to evaluate the impact of different nutrient management practices on content and quality of soil humus in a newly developed terraced land. Twelve treatments involving N, P and K (NPK) fertilizers, farmyard manure (FYM), poultry litter, forest litter, Azospirillum and Zn either alone or in combinations were applied continuously for two years. On an average, fulvic C, humic C and humin C was 48.1, 21.1 and 30.8% of humus C, respectively. The fulvic C was the largest fraction of humus C in soil followed by humin C and humic C. With the present rate of accumulation of humus C, the soil under different treatments showing build up of humus C would take 3.5 to 66.0 years with an average of 23.2 years to reach its original C content present before terracing. Among the fractions, fulvic N was the largest fraction of humus N in all the treatments followed by humic N or humin N. On an average, fulvic N, humic N and humin N was 58.8, 21.2 and 20.0% of humus N, respectively. After two years, the rate of build up of humus N in various nutrient management practices was 18.3 to 76.4 kg N ha-1 yr-1 with an average of 44.5 kg N ha-1 yr-1. Among the fractions, fulvic P was the largest fraction of the humus P followed by humic P and humin P in all the treatments. On an average, fulvic P, humic P and humin P constituted 65.4, 20.5 and 14.1% of humus P, respectively. The lowest C:N:P ratio of soil humus, fulvic acid and humic acid was in NPK+Poultry litter treatment. The average C:N:P ratios of soil humus, fulvic acid, humic acid and humin was estimated to be 133.

The impact of long term nutrient management practices on soil fertility determinants and performance of upland rice after thirteen years of continuous cultivation on terraced land were studied in a field experiment conducted on the experimental farm of the School of Agricultural Sciences and Rural Development under rainfed conditions. Twelve treatments involving N, P and K (NPK) fertilizers, FYM, poultry litter, forest litter, Azospirillum and Zn either alone or in combinations were applied for thirteen years and rice crop cultivated continuously. The organic C content, available N, P and K, number of productive tillers, grain and straw yield increased significantly in all the treatments. The highest accumulation of available N, P and K was observed in NPK+ poultry litter, NPK+ FYM and ½N + PK + ½N forest litter treatments, respectively. After thirteen years the rate of build up of available N, P and K in different nutrient management practices ranged from 5.2 to 16.9, 0.33 to 0.80, and 1.96 to 7.03 ha-1 yr-1 , respectively. Addition of FYM and poultry litter with NPK increased 28.7 and 25.9 per cent in grain yield and 50.3 and 49.4 per cent in straw yield, respectively as compared to NPK alone.

An experiment was conducted in the experimental farm at School of Agricultural Sciences and Rural Development, Medziphema, Nagaland to find out the impact of continuous fourteen years integrated nutrient management practices on forms of soil N and P on terraced land. Twelve treatments involving N, P and K fertilizers, farmyard manure, poultry litter, forest litter, Azospirillum and Zn either alone or in combinations were applied continuously for fourteen years. The highest NH 4-N content was recorded in NPK+ FYM+ Zn followed by NPK+ FYM treatment, whereas the highest NO 3-N content was in NPK followed by NPK+ FYM and NPK+ FYM+ Zn treatments. After fourteen years, the rate of build up of available N in different nutrient management practices was 0.5 to 10.3 kg N ha-1 yr-1 with an average of 5.8 kg N ha-1 yr-1 whereas, the rate of build up of total N in various nutrient management practices was 1 2.8 to 16.1 kg N ha-1 yr-1 with an average of 11.2 kg N ha-1 yr-1. The significant increase in organic N in NPK+ FYM, NPK+ poultry litter and NPK+ FYM+ Zn treatments over NPK was 5.7, 5.0 and 5.4 per cent, respectively. The inorganic P in NPK+ poultry litter, NPK+ FYM+ Zn and NPK+ FYM was 5.8, 3.8 and 2.2 per cent higher as compared to NPK, respectively. The rate of build up of available P in different treatments was 0.01 to 0.76 kg P ha-1 yr-1 with an average of 0.49 kg P ha-1 yr-1. On an average, solution P, inorganic P, available P and organic P represented 0.3, 40.6, 3.3 and 59.6 per cent of total P.

A field experiment was carried out to evaluate the effects of simulated erosion and the impact of organic manures on soil physico-chemical properties. The experiment was conducted in split-plot design which comprised of three levels of simulated erosion depths viz., 0, 5 and 10 cm used as the main plot. Organic manures (vermicompost, poultry manure and pig manure @ 5, 3 and 3 t-1 ha, respectively) were used as the sub plot treatment. There was a significant effect on the physico-chemical properties of soil due to erosion. The available nitrogen decreased at a rate of 2.86 and 7.81 per cent; available P decreased at a rate of 9.09 and 17.18 per cent; available K decreased at a rate of 9.52 and 15.12 per cent; organic carbon decreased at a rate of 0.07 and 0.15 per cent; CEC decreased at a rate of 2.81 and 5.48 per cent; water holding capacity decreased at the rate of 4.07 and 7.29 per cent while bulk density increased at a rate of 3.49 and 9.30 per cent and soil pH decreased at a rate of 4.12 and 7.20 per cent, respectively with subsequent removal of 5 and 10 cm topsoil as compared to control. Addition of organic manures improved the soil properties but could not entirely compensate the loss due to simulated erosion.

The experiment was carried out at, Faculty of Agriculture, Wadura-Sopore, SKUAST-K during 2017-2018, to study "Soil Physico-chemical properties in some soils of district Baramulla under different Land use systems". The land use systems studied included apple, paddy, maize, vegetables, forest and pasture. Composite soil samples were collected randomly for each land use system at a depth (0-20 cm) and were analyzed for soil texture, pH, EC, CEC, organic carbon and calcium carbonate. The soils were found to possess medium to moderately fine texture. K e y w o r d s Soil, Physicochemical properties, Land uses