Papers by B. Venkateswarlu
Indian Journal of Microbiology, 2009
Agriculture is considered to be one of the most vulnerable sectors to climate change. The average... more Agriculture is considered to be one of the most vulnerable sectors to climate change. The average temperature in the Indian sub-continent has risen by 0.57°C in the last 100 years and models project that it is likely to rise further to a maximum of 2.5°C by 2050 and 5.8°C by 2100. Besides high temperature, elevated CO 2 , extreme rainfall events, more fl oods, cyclones, cold waves, heat waves and frost are other effects likely to be witnessed as a result of global warming. The irrigation requirement of crops in arid and semi-arid regions is estimated to increase by 10% for every 1°C rise in temperature. These factors are likely to cause serious negative impacts on crop growth and yields and impose severe pressure on our land and water resources.
Advances in Agroforestry, 2013
Agroforestry in rainfed areas increases livelihood security through simultaneous production of fo... more Agroforestry in rainfed areas increases livelihood security through simultaneous production of food, fodder, and firewood, and an increase in total productivity per unit area of land. Management of trees in conjunction with crops in rainfed areas minimizes the risk associated with stress period through diversified components and through efficient utilization of limited natural resources. The major objective of agroforestry in rainfed areas is gainful utilization of off-season precipitation, income stabilization, soil and water conservation, insurance against weather aberrations and mitigation of climate change. In India, agroforestry practices in rainfed agriculture have been used to manage scattered trees on farm lands, trees on farm bunds, wood lots as block plantations, trees on range lands, and vegetative live hedges for ecological, social, and economic functions. To enhance rural livelihood security among the dryland farmers, several improved agroforestry systems, commercial plantations and biofuels and bioenergy systems came into being for adoption. Agroforestry plantation-based success stories reveal livelihood security of small, marginal, and landless farmers. Steps to promote basic and promotional agroforestry research in dryland agriculture and appropriate policy responses with extension outreach may potentially deliver better results in rainfed agriculture. Rainfed agroforestry for livelihood security reflects the positive way in utilization of rainfed area resources.
Advances in Agronomy, 2013
ABSTRACT
3 Biotech, 2011
Cellulose is a major constituent of renewable lignocellulosic waste available in large quantities... more Cellulose is a major constituent of renewable lignocellulosic waste available in large quantities and is considered the most important reservoir of carbon for the production of glucose, for alternative fuel and as a chemical feedstock. Over the past decade, the emphasis has been on the enzymatic hydrolysis of cellulose to glucose and the efficiency of which depends on source of cellulosic substrate, its composition, structure, pretreatment process, and reactor design. In the present study, efforts were made to produce cellulase enzyme using rice straw. The produced enzyme was used for the hydrolysis of selected lignocellulosic substrate, i.e., sorghum straw. When rice straw was used as a substrate for cellulase production under solid state fermentation, the highest enzyme activity obtained was 30.7 FPU/gds, using T. reesei NCIM 992. 25 FPU/g of cellulase was added to differently treated (native, alkali treated, alkali treated followed by 3% acid treated and alkali treated followed by 3 and 5% acid treated) sorghum straw and hydrolysis was carried out at 50°C for 60 h. 42.5% hydrolysis was obtained after 36 h of incubation. Optimization of enzyme loading, substrate concentration, temperature, time and buffer yielded a maximum of 546.00 ± 0.55 mg/g sugars (54.60 ± 0.44 g/l) with an improved hydrolysis efficiency of 70 ± 0.45%. The enzymatic hydrolyzate can be used for fermentation of ethanol by yeasts.
The objectives of this study were to examine the effects of 20 years of groundnut cropping with c... more The objectives of this study were to examine the effects of 20 years of groundnut cropping with chemical fertilization (NPK), organic manuring (FYM or groundnut shells) and integrated use of these two inputs (INM) on crop yields, soil organic carbon (SOC), particulate organic carbon (POC) and microbial biomass carbon (MBC) in an Alfisol under arid conditions. Various nutrient management options significantly (<0.05) improved yield of groundnut pod over 20 years. The SOC improved significantly in surface layer (0-20 cm) from 0.31 % in control to 0.59 % in 50 % NPK + 4 t FYM ha-'. With 50 % NPK + 4 t groundnut shells ha-1 also the SOC improved markedly to 0.49 %. Interestingly, with integrated nutrient use, improvements in SOC were observed even up to 60 cm depth of the profile. Overall, there was a buildup of SOC in surface layers in all treatments. Profile mean POC increased from 0.09 % in control to 0.20 % in 50 % NPK + 4 t FYM ha-1 • Microbial biomass carbon (MBC) improved from 31.5-54.9 µg g-1 soil in control to 39.5 -135.5 µg g-1 soil with 50 % NPK + 4 t FYM ha-1 , whereas the highest MBC/OC ratio was found in 50 % NPK + 4 t groundnut shells ha-1 .
The present study assesses contribution of goats to the livelihood of rural poor in the semi-arid... more The present study assesses contribution of goats to the livelihood of rural poor in the semi-arid regions of India. It is based on primary data collected from semiarid zones of Uttar Pradesh and Rajasthan during the year 2001-2002. The goat rearing was a major source of livelihood mainly for landless, marginal and small farmers, and rural woman, but in Rajasthan the large farmers had also widely adopted it. The flock size in different categories varied from 2.43 to 36 breedable goats in Uttar Pradesh and 3.47 to 45.59 breedable goats in Rajasthan. The resource flows showed that the goat production component had strong linkages with other components of the farming system and was largely dependent on the common grazing resources. Resource use structure including housing, feeding systems, flock management and labour utilization pattern were also examined. A regression was tried to ascertain the determinants of flock-size. The existence of scale economies was also assessed through cost analysis and regression function. The access and control profile reflected the gender participation in goat rearing and its significance for women empowerment. On an average goat-keeper's family earned a net annual income of Rs. 1216 to Rs. 1819 per goat in different categories and goats contributed up to 85 percent of the total income of the family. The Losses due to diseases, scarcity of fodder and poor realization of price of produce were found to be the major constraints in goat rearing. Degradation in the quality of breeding animals and poor access to improved technologies and critical inputs were other major constraints. Low adoption of improved technologies was constraining the productivity of goats. Finally the paper draws implications for development of goat farming.
Production and application of biochar from small-scale units on farm level may solve several envi... more Production and application of biochar from small-scale units on farm level may solve several environmental problems. The aim of the study was to develop a low cost portable kiln and to investigate the relationship between the production parameters with biochar characteristics. On-farm usable portable kiln unit (approx. cost per kiln was ₹ 1200) was developed on a single barrel design of vertical structure with perforated base and design function with direct up-draft principle. Cotton stalk bioresidues were subjected to thermo-chemical conversion at different loading rates and holding time. Holding time for each loading rate was correlated with internal kiln temperature. Grey gas colour was correlated with to 350-400˚C and blue gas colour to 450-500˚C kiln temperature range. Volatile matter content decreased, whereas fixed carbon and ash content increased with increase in temperature in each load. Biochar yield decreased with increasing temperature in each load types. Total C and N content of the biochars ranged between 592.4 to 719.3 g/kg and between 10.3 to 17.4 g/kg, respectively. The amount of total C and N recovered in the biochar ranged from 26 to 38% and 16 to 34%, respectively. Total P, K, Ca, Mg, Fe, Cu, Mn and Zn contents were higher in biochar compared to raw cotton stalk. The CEC of the biochar samples ranged from 11.7 to 51.3 cmol/ kg. Highest maximum water holding capacity (3.9 g/g of dry biochar) and available water capacity (0.89 g/g of dry biochar) was exhibited at highest at 450-500˚C. Therefore, cotton stalk biochar produced at 450-500˚C showed the greatest potential for use as soil amendment to improve the fertility of rainfed soils as well as to sequester carbon.
Uploads
Papers by B. Venkateswarlu