Biomass, Biochemical Composition and Decomposition Behavior of Roots and Shoots of Major Rainfed Crops

Not AvailableA Study was conducted during 2012-14 to quantify root and shoot biomass of 2 cultivars each of 8 rainfed crops (sorghum, greengram, sunflower, maize, castor, pigeonpea, cowpea and horsegram), to determine their biochemical composition and to examine their decomposition behavior in soil. Root biomass of all the crops and cultivars was lower than the respective shoot biomass. Roots accounted for 12.07% (Horsegram, CRHG 4) to 35.26% (Maize, DHM 117) of the total plant biomass. Root biomass (averaged over cultivars) varied widely with crops, ranging from as low as 5.24 g/plant (Horsegram) to as high as 158.23 g/plant (Pigeonpea) and was in the order pigeonpea > sorghum > maize > castor > sunflower > cowpea > greengram > horsegram. Shoot:root ratios ranged from 1.84 (Maize, DHM 117) to 7.29 (Horsegram, CRHG 4). There were marked differences in shoot:root ratios among crops and even cultivars within crops. Biochemical analysis revealed that cell wall was the dominant fraction of the plant tissue accounting for up to 3/4th of the tissue. Regardless of crop or cultivar, roots had lower soluble cell contents and higher cell wall contents than shoots. Averaged across crops and cultivars, lignin content of roots was 13.76% as against 8.38% for shoots. Crops differed significantly in the lignin content of their roots, which ranged from 8.25% in maize to 19.15% in pigeonpea. The dicots with taproot systems (castor, sunflower, greengram, cowpea, horsegram, pigeonpea) had higher lignin content than the monocots with fibrous root systems (maize, sorghum). Lignin/N ratios of roots were 2-3 times higher than those of shoots. Patterns of carbon mineralization of roots and shoots were exponential in nature, being faster in the initial stages and slowing down over time. Regardless of crops and cultivars, roots exhibited distinctly slower carbon mineralization than corresponding shoots. Averaged across crops and cultivars, per cent C mineralized in 120 days was 37.35% in roots as against 50.22% in shoots. Lignin content (r = -0.684 * * ) and lignin/N ratio (r = -0.636 * * ) had a highly significant negative relationship with % C mineralized.Not Availabl

Not Available

Not AvailablePhosphorous Use Efficiency of crops is evaluated in terms of apparent recovery, agronomic efficiency and physiological efficiency and is generally low in crops. The agronomic management, fertiliser management , soil management and development of efficient plant root systems, using mycorrhizal association and plant microbial strategies are some of the strategies developed to improve P use efficiency in different crops/ cropping systems. Among the various fertilizer management strategies fertigation is best approach as it not only increases the efficiency but also increases yield and protects environment. P utilization can also be increased by increasing the effective root area and by modifications in rhizosphere. However to increase the P use efficiency in India measures should be advocated by the Govt. to encourage use of partially acidulated phosphate rocks which are less costlier than SSP in neutral to alkaline soils with medium P in long term crops and cropping systems. Further focused research on development of CRF’s like polymer blended P, exchanger P, coating of P with nano particles and varieties with high P acquisition efficiency is essential.Not Availabl

Not Available

Not AvailableOften the terms ‘drylands’ and ‘rainfed regions’ are used synonymously. Though they overlap to a large extent, dryland area is a piece of agricultural land having no source of irrigation including groundwater. Dryland Agriculture is defined as cultivation of crop entirely with rainwater received during the crop season or stored/ conserved soil moisture or supplemented with harvested rainwater. Time and again the crop experiences mild to very severe moisture stress during cropping period in dryland areas. Drylands are characterized by having (i) limited rainfall up to 1000 mm; (ii) shortage of moisture availability; (iii) growing season of less than 200 days; (iv) single crop or intercropping system, and (v) constraints of water and wind erosion. There is no single agreed definition of the term drylands. Two of the most widely accepted definitions are those of FAO and the United Nations Convention to Combat Desertification (UNCCD, 1994). FAO has defined drylands as those areas with a length of growing period (LGP) of 1-179 days (FAO, 2000); this includes regions classified climatically as arid, semi-arid and dry sub-humid. The UNCCD classification employs a ratio of annual precipitation to potential evapotranspiration (P/PET). UNCCD (United Nations Convention to Combat Desertification) defines drylands based on aridity index (la) computed as ratio of mean annual precipitation (P) to mean annual potential evapotranspiration (PET). Accordingly, areas with arid (Ia=0.05-0.20), semi-arid (Ia=0.20-0.50) and dry sub- humid (Ia=0.50-0.65) climates are termed as drylands (UNCCD, 1994). While about 40 percent of the world’s total land area is considered to be drylands (according to the UNCCD classification system), the extent of drylands in various regions ranges from about 20 to 90%.Raju et al. (2014) computed aridity index using the district level annual rainfall and PET data for years 1971-2005 and identified districts in India having dryland climates. Net sown area (mostly average of two years: 2007-08,2008-09) of districts with dryland climates adds up to 85 m ha (approximate).Not Availabl

Not Available

Not AvailableNot AvailableNot Availabl

Not Available

Not AvailableThermally promoted phosphate rocks (TPPRs) were prepared by heating four phosphate rocks (PRs) obtained from Jhabua, Mussoorie, Purulia and Udaipur alone or with two additives (Na2CO3 or KCl) in three ratios at four temperatures (300, 500, 700 and 900°C) for two hours. All the 112 TPPRs so prepared, were analyzed for total, citrate and water-soluble P contents. Characterization of TPPRs indicated that irrespective of the source of phosphate rocks, the total P content of TPPRs prepared with additives was less as compared to original phosphate rocks. In general, Jhabua PR registered the highest total P content. The total P content increased with increase in temperature, but decreased with increase in the PR to additive ratios. TPPRs of Na2CO3 registered higher amounts of total P as compared to KCI. Water and citrate soluble P contents of TPPRs increased with increase in temperature, and PR to additive ratios. Among the four phosphate rocks, Mussoorie PR recorded the highest amount of water and citrate soluble P in heated-products. TPPRs obtained with Na2CO3 registered higher amount of water and citrate soluble P contents as compared to those prepared with KCl. The X-ray diffractograms of TPPRs indicated the presence of citrate soluble NaCaPO, and water soluble Na2PO3 in the products obtained from PR-Na2CO3 mixtures heated at 900°C.Not Availabl

Not Available

Not AvailableA field experiment was conducted during the rainy season of 2000 and 2001 on deep Vertisols of Bhopal, to study the effect of soybean [Glycine max (L.) Merr.] and sorghum [Sorghum bicolor (L.) Moench] intercropping (2:1 row ratio) in comparison to their sole crops at 3 levels of nitrogen (0, 75 and 100% recommended dose). Sole sorghum recorded higher seed, straw and soybean-equivalent yield (SEY) compared to either sole soybean or soybean + sorghum intercropping. However at N0, soybean + sorghum intercropping resulted in higher SEY and at higher N status (75 or 100%), sole sorghum resulted in higher SEY. Nitrogen-uptake was higher in sole soybean, whereas P and K uptake were higher in sole sorghum. Sole sorghum recorded higher nutrient-use efficiency (NUE), whereas sole soybean resulted in lower NUE. However, nutrient harvest index of NPK were higher in sole soybean and lowest in sole sorghum. Increased N levels significantly improved the SEY, nutrient uptake and agronomic and recovery efficiency of NPK. However, physiological efficiency and nutrient harvest index of NPK were not affected due to increased N levelsNot Availabl

Not Available

Not AvailableThermally promoled phosphale rocks (TPPRs) were prepared by heating phosphale rock samples obtain ftom Jhabua, Mussoorie, Purulia and Udaipur deposits alone or wilh Na, CO, or KCI in lwo PR to additive ratios at 500, 700 and 900°C and applied to a soil @ 50 and 100 mg P kg−1 soil. Treated soils were ihcubated for 120 days at a temperature of 35±1°C and soil water content of 50 per cent of field capacity. Throughout the incubation period, phosphate treated soil samples maintained a higher level of Olsen P status as compared to control. TPPRs from Mussoorie rock were superior during lhe first six fortnights of incubation over olhers and subsequently it became on par wilh Udaipur rock in the remaining period of incubation. TPPRs prepared with Na,CO, maintained higher extractable P status in soils over those obtained with KCI. Increase in temperature or P rate was accompanied by a concurrent improvement in extractable P status of the soil. In general, after 45 days of incubation, the extractable P concentration dropped rapidly irrespective of sources of PRs, additives, temperature, PR 10 additive ratios and levels of P application.Not Availabl

Not Available

Not AvailableIn a 2!year experiment on a Typic Haplustert low in soil test sulphur "S# \ the response to applied farmyard manure "FYM# and S was studied in terms of the nodule production \ nodule dry weight \ chlorophyll content \ dry matter production and seed yield of soybean FYM was applied to soybean at four levels "9 05 t ha 0# S as gyp! sum was also applied at four levels "9 59 kg ha 0# to both soybean and wheat every year Both total and active nodule production \ nodule dry weight \ dry matter pro! duction and seed yield of soybean were increased sig! ni_cantly by the application of both FYM and S However \ the proportion of total nodules to active nod! ules fell sharply for applications higher than 7 t FYM and 39 kg S ha 0Not Availabl

Not Available

Not AvailableA field experiment was conducted on deep Vertisols during 2000–2001 to 2001–2002 to determine the production potential and nutrient balance of 3 cropping systems involving soybean [Glycine max (L.) Merr.], sorghum [Sorghum bicolor (L.) Moench] and their intercropping at 3 levels of fertility, viz. 0, 75 and 100% recommended dose of nitrogen (RDN) during rainy season (kharif), followed by wheat (Triticum aestivum L. emend. Fiori & Paol.) at 100% RDN during winter (rabi). Sole sorghum at 100% RDN recorded higher productivity, while the wheat productivity was highest when it was preceded by sole soybean at 100% RDN. However, sorghum - wheat cropping system at 100% RDN recorded the highest total productivity of 5,003 and 5,033 kg/ha of soybean-equivalent yield in 2000–2001 and 2001–2002 respectively. This cropping system recorded the total uptake of 475.9, 76.3 and 466.7 kg/ha of N, P and K, respectively, and resulted in a positive balance of 10.6, 4.9, and 12.4 kg/ha of available soil N, P and K, after 2 years. However, soybean-based cropping systems enriched the soil-N, especially with the application of recommended doses of N.Not Availabl

Not Available

Not AvailableThe article analyzed the macro-economic policies and budgetary allocation to natural resource management related schemes in India. The drylands are neglected in investments and policy issues for long. Special emphasis needs to be given to dryland areas and crops in budget especially in the ongoing schemes like Pradhan Mantri Krishi Sinchai Yojana, Pradhan Mantri Fasal Bima Yojana, Rashtriya Krishi Vikas Yojana and NMSA.Not Availabl