Among the different controls of erosion budget at basin level, the relative impact of dams and land management is yet to be investigated. In this paper, the impact of dams on sediment yield has been assessed by using a conceptual modelling framework which considers the gross erosion and the cascade of dams constructed on a river network. The sediment budget has been estimated based on the gross erosion, deposition of sediment in reservoirs, and sediment yields of 23 mainland river basins of India. The gross erosion of the country is estimated as 5.11 ± 0.4 Gt yr−1 or 1559 t km−2 yr−1, out of which 34.1 ± 12% of the total eroded soil is deposited in the reservoirs, 22.9 ± 29% is discharged outside the country (mainly to oceans), and the remaining 43.0 ± 41% is displaced within the river basins. The river basins of northern India contribute about 81% of the total sediment yield from landmass while the share of southern river basins is 19%. The components of revised sediment budget for India are prominently influenced by the sediment trapped in reservoirs and the treatment of catchment areas by soil and water conservation measures. Analysis of sediment deposition in 4937 reservoirs indicated the average annual percentage capacity loss as 1.04% though it varies from 0.8% to >2% per year in smaller dams (1–50 Mm3 capacity) and from <0.5% to 0.8% per year in larger dams (51 to >1000 Mm3 capacity). Siltation of smaller dams poses a serious threat to their ecosystem services as they cater to a wider population for domestic, agricultural, and industrial purposes. Amongst the environment controls, land use significantly impacts the gross erosion rate and specific sediment yield as compared to climatic and topographic parameters. However, to analyse their integrated effect on the complex processes of sediment fluxes in a basin, further research efforts are needed. Copyright © 2016 John Wiley & Sons, Ltd.

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Due to extensive root system, connected rhizome bamboos are considered suitable for improving soil properties within a short period, though most of the claims are anecdotal and need to be supported with quantified data. The study evaluates seven bamboo species viz., Bambusa balcooa, Bambusa bambos, Bambusa vulgaris, Bambusa nutans, Dendrocalamus hamiltonii, Dendrocalamus stocksii and Dendrocalamus strictus for their rooting pattern and impact on soil health properties. Coarse and fine root intensity was maximum in B. vulgaris. Coarse root biomass ranged from 0.6 kg m −3 in B. nutans to 2.0 kg m −3 in B. vulgaris and B. bambos. Fine root biomass ranged from 1.1 kg m −3 in B. nutans to 4.5 kg m −3 in D. hamiltonii. Contribution of fine roots in terms of intensity and biomass was much higher than coarse roots. Fine root biomass showed declining trend with increase in soil depth in all the species. During sixth year, the litter fall ranged from 8.1 Mg ha −1 in D. stocksii to 12.4 Mg ha −1 in D. hamiltonii. Among soil physical properties significant improvement were recorded in hydraulic conductivity, water stable aggregates and mean weight diameter. Soil pH, organic carbon and available phosphorus under different species did not reveal any significant changes, while significant reduction was observed in total nitrogen and potassium. Significant positive correlation was observed between WSA and iron content. Soil microbial population and enzyme activities were higher in control plot. Considering root distribution, biomass, soil hydraulic conductivity and water stable aggregates, B. bambos, B. vulgaris and D. hamiltonii are recommended for rehabilitation of degraded lands prone to soil erosion. Bamboo grows worldwide in at least 37 million ha and covers 3.2 percent of forest areas of their host countries, or about 1 percent of the global forest area 1. Bamboo being an annual yielding crop with multipurpose utility has proven potential for contributing to poverty reduction, environmental protection and achievement of United Nations Sustainable Development Goals-SDG1, SDG7, SDG 11, SDG 12, SDG 13, SDG 15, and SDG 17 2. Many countries are now exploring options for achieving land degradation neutrality through the use of bamboo. Bamboo also contributes to the Bonn Challenge, the global initiative targeting the restoration of 200 million hectares of the planet's degraded lands, to which International Bamboo and Rattan Organization (INBAR) member states have agreed to contribute about five million hectares of bamboo plantations 3. India is the second richest country of the world, after China, in terms of bamboo genetic resources 4. The bamboo area of the country is estimated to be 15.69 million hectare with total standing stock of 189 million tons 5. Raising of bamboo on degraded soils improves soil quality and sequesters carbon in the soil 6,7. Bamboo due to its fast growth and extensive root system improves soil physical, chemical and biological properties; controls soil erosion; filters sediment and is considered suitable...

Soybean–wheat cropping system is the most commonly used in the black soil of India which produces enormous amounts of nutrient‐rich residues. However, black soil has some production limitations, such as rapid drying, high bulk density, low nutrients, and poor microbial populations, making it vulnerable to degradation. Optimal retention of soybean and wheat residues in black soil under the zero‐tillage (no‐till) system can improve soil properties and help protect the land from degradation. Thus, the main objective of this study was to test the effect of different levels of soybean and wheat residue retention on the physical, chemical, and biological properties of black soil. Therefore, an experiment was conducted in the zero‐tillagesoybean–wheat system at the Indian Institute of Soil Science, Bhopal, India from 2014 to 2018. In this study, the effect of four levels of soybean and wheat residue retention (no residue, 30, 60, and 90%) on soil properties was evaluated. Results revealed that soil organic carbon (C) significantly increased from 0.67 to 1.0% in 5 years through 90% residue retention. Retaining 90% (7.0 t) of soybean residue added 2.9 t C, 197.3 kg nitrogen (N), 32.4 kg phosphorus (P), and 89.7 kg potassium (K) in 5 years, while 6.2 t C, 85.7 kg N, 15.3 kg P, and 232.2 kg K were added through 90% (13.8 t) wheat residue during the same period. Different pools of soil C (oxidizable, labile, and particulate organic matter (OM)‐carbon), soil OM, soil moisture, soil porosity, available nutrients, and bacterial, fungal, and actinomycetes count was significantly enhanced due to retention of 90% residue over 60 and 30%. It was observed that retention of 90% soybean and wheat residues (7.0 and 13.8 t ha−1, respectively) significantly improved the physical, chemical, and biological properties of black soil in 5 years, therefore protected the soil from degradation.

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Principal component analysis of white oak (Quercusalba L.) and black oak (Quercusnigra L.) revealed different stem profiles across four ecological land units in the Lower Peninsula of Michigan. Multivariate linear regression and geometric models were developed to predict DBH from stump diameter for both species. For the multivariate model, the prediction variables were stump diameters at 15 and 30 cm above the ground level. The geometric model uses stump diameter at any height. Both the multivariate and geometric models can be used to predict DBH; however, the geometric models have the advantage of using fewer variables and being more flexible than the multivariate models.