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Soil erosion by water has a debilitating effect on crop productivity. Though limited and scattered data is available on loss of production due to water erosion in India, no systematic effort has been made to compute the losses in crop production based upon experimental data, major soil groups, and prevailing erosion rates. The objective of this study is to estimate on-site physical and economic loss of production of major cereal, oilseed, and pulse crops cultivated on rainfed areas of India due to soil erosion by water. The estimation is done by integrating the available experimental data of a crop with the rainfed area of that crop under each erosion intensity category for each of the three major soil groups (alluvial, black and red) in a given state. Following this approach, the total production loss due to water erosion of rainfed areas under major cereal, oilseed, and pulse crops in India was observed to occur at 16%, which in actual physical terms was estimated as 13.4 million t (13.2 million tn) and in economic terms as $2.51 billion (INR 111.3 billion) (the conversion has been given in US dollars as per average conversion rate of 2005 to 2006, i.e., at INR 44.273 per US dollar). Among the six zones of India, the average production loss occurred within a range of 10% (northern) to 24% (southern). At state level, the production loss ranged from 1.4% in Punjab and Haryana states located in alluvial Indo-Gangetic Plains to 41% in the erosion-prone northeastern Himalayan state of Nagaland. In terms of production loss among major groups of crops, cereals contributed 66% to the total loss, followed by oilseeds (21%) and pulses (13%). A similar trend was observed for the monetary losses amounting to 45% for cereals, 33% for oilseeds, and 22% for pulses. Paddy was the most affected among all the crops in terms of both production (4.3 million t [4.23 million tn]) and monetary ($0.56 billion [INR 24.4 billion]) losses. Since the losses are cumulative over time, it is imperative to undertake appropriate soil and water conservation measures for rehabilitation of rainfed areas to prevent huge declines in their productivity levels, which may escalate further due to population pressures.

Despite years of study and substantial investment in remediation and prevention, soil erosion continues to be a major environmental problem with regard to land use in India and elsewhere around the world. Furthermore, changing climate and/or weather patterns are exacerbating the problem. Our objective was to review past and current soil conservation programmes in India to better understand how production-, environmental-, social-, economic-and policy-related issues have affected soil and water conservation and the incentives needed to address the most critical problems. We found that to achieve success in soil and water conservation policies, institutions and operations must be co-ordinated using a holistic approach. Watershed programmes have been shown to be one of the most effective strategies for bringing socio-economic change to different parts of India. Within both dryland and rainfed areas, watershed management has quietly revolutionized agriculture by aligning various sectors through technological soil and water conservation interventions and land-use diversification. Significant results associated with various watershed-scale soil and water conservation programmes and interventions that were effective for reducing land degradation and improving productivity in different parts of the country are discussed.

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...

Estimated annual production losses from rainfed cereal, oilseed and pulse crops at state, zonal and national levels do not provide a comparative picture of the severity of losses in different areas and crops leading to decline in production on per-unit area basis. In this paper, productivity or per-unit area production losses have been estimated for the considered rainfed crops to identify the states/regions in the country where intensive conservation measures need to be adopted to bring erosion within permissible limits and to restore the productivity of these crops to their potential capacity. Further, productivity losses were valued at government minimum support prices of the study crops to compute the monetary losses in the major cereal, oilseed and pulse crops in the country. It was observed that productivity loss in rainfed cereals at state level ranges from 0.2-10.9 q/ha, for oilseeds 0.1-6.3 q/ha and for pulses 0.04-4.4 q/ha. These losses in the states having relatively smaller areas under these crops and are low ranked in terms of total production loss, such as northeastern states, Goa, Kerala and Uttarakhand, are 2-5 times higher than the national average and are placed in top 8-10 ranks of affected states, thus justifying the need to estimate productivity losses rather than the production losses. The northeastern states, though account for only 4 % of rainfed area under considered crops, are the leading states in terms of productivity losses. India as a whole suffers a loss of 1.63 q/ha in productivity of rainfed crops, which is valued at Rs. 2,484/ha. In absolute terms, the annual production losses are 13.4 Mt valued at Rs. 205.32 billion considering minimum support price of 2011/12. About 53 % of total monetary loss is accounted for by paddy, groundnut, soybean and maize crops due to water erosion.

Vegetation strips (VS) along with conservation tillage, application of organic amendments and weed mulching improve crop yields by reducing run‐off and topsoil erosion. To investigate these issues, an experiment was conducted under rainfed conditions using grass VS for four and a half years (June 2007 to October 2011) at Dehradun, Uttarakhand, in the Indian Himalayan region. VS were incorporated in the experimental plots (Entisols) in a randomized complete block design in permanent 100 × 20 m (2000 m2) plots with a 2% slope to evaluate the effects of vegetation strips on run‐off, soil loss and crop yield. Three treatments were evaluated: (i) without VS with recommended NPK under conventional tillage, (ii) panicum as VS with recommended NPK under conventional tillage and (iii) palmarosa+ that consists of palmarosa as VS along with organic amendments (farmyard manure, vermicompost and poultry manure) and weed mulch under minimum tillage. The results show that soil loss and run‐off were significantly lower (P < 0.05) in plots under palmarosa+ than without VS treatment. Mean soil loss of 3.4, 5.2 and 7.1 t/ha was recorded from palmarosa+, panicum and without VS treated plots, respectively. Mean run‐off was 234, 356 and 428 mm from plots under palmarosa+, panicum and without VS, respectively. Maize yield was lower on the plots under palmarosa+ compared with panicum, but significantly higher (P < 0.05) than without a strip. The succeeding rainfed wheat yield was significantly greater in plots under palmarosa+ than in the initial years. The wheat yield equivalent was significantly higher in plots under palmarosa+ followed by panicum and without VS. Thus, vegetation strips are recommended for wider adoption to reduce run‐off and soil loss and to increase crop yield. The long‐term goal is to achieve a palmarosa+ system (palmarosa as a vegetation strip along with organic amendments, farmyard manure, vermicompost and poultry manure) and weed mulch under minimum tillage.

A total of 15 years of experimentation period (1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010) was divided into two phases. In the first phase (1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005), five mango based agri-horticultural models (AHM) viz. Mango ? cowpea-toria, mango ? cluster bean/okra-toria, mango ? sesametoria, mango ? black gram-toria and mango ? pigeon pea in addition to sole mango plantation (no intercrop) and in second phase (2005)(2006)(2007)(2008)(2009)(2010), two mango based AHM (mango ? colocasia and mango ? turmeric) in addition to sole mango (no intercrop) were studied. The mean maximum cowpea equivalent yield (t ha -1 ) was harvested from cowpea (1.84) followed by okra (1.21), black gram (1.11), sesame (0.68) and mean minimum with pigeon pea (0.58). The crop yield reduction among the mango based AHM was observed from third year to tenth year. The positive correlation was found between light transmission and intercrops yields amongst all models during both phases. However, the correlation between mango canopy spread and intercrop yields shown negative trends. The yield reduction in intercrops varied from 37.0-52.6 % during first phase and 20.6-23.5 % during second phase of experimentation compared to sole crop. The results revealed that the fruit based AHM were effective in improving fruit yields of the mango. The mean maximum fruit yield of mango (7.02 t ha -1 ) was harvested with cowpea-toria crop rotation followed by black gram-toria (6.59 t ha -1 ) and minimum fruit yield (5.76 t ha -1 ) realized with sole mango tree during first phase (1999)(2000)(2001)(2002)(2003)(2004)(2005). Likewise, mean maximum fruit yield (13.71 t ha -1 ) from mango tree was obtained in the turmeric block followed by (13.00 t ha -1 ) in colocasia block and minimum fruit yield with sole mango tree (11.86 t ha -1 ). All the treatments of AHM recorded higher soil moisture as compared to sole mango plantation during both phases. The moisture retention under different AHM was in the order of cowpea (13.32 cm) [ black gram (13.29 cm) [ pigeon pea (13.27 cm) [ okra (12.42 cm) [ sesame (12.17 cm) [ sole mango (11.62 cm) during first phase, whereas moisture retention was observed in the order of turmeric (14.20 cm) [ colocasia (14.01 cm) [ sole mango (12.60 cm) during second phase. The cowpea-toria crop rotation with mango gave maximum benefit: cost ratio followed by okra-toria under rainfed conditions. Besides economic viability of cowpeatoria with mango, this system had improved tree growth as well as fruit yield of mango. In the second phase, mango ? turmeric yielded more benefit than mango ? colocasia system. In the first phase, the mango ? cowpea-toria system improved organic carbon, total nitrogen, phosphorus, potash and reduced pH by 49.0, 56.3, 48.6, 58.5 and 11.6 %, respectively as compared to initial values whereas mango ? turmeric system increased organic carbon, nitrogen, phosphorus, potash and reduction in pH by 51.0, 45.0, 29.7, 29.0 and 3.4 %, ...