An experiment was conducted for two years during kharif 2009 and 2010 at College Farm, College of Agriculture, Rajendranagar, Hyderabad, India to study the effect of organic sources and fertilizer levels on spikelet sterility in hybrid rice (Oryza sativa L.). The experiment was laid out in split plot design with three replications. The treatments included organic manures (control – no organic manuring, subabul incorporation @ 5 t ha−1, rice straw incorporation @ 2.5 t ha−1) as main plot treatments and fertilizer levels comprising of N:K2O kg ha−1 (150:75, 175:50, 175:25, 200:50, 200:25, 225:0) as sub plot treatments. Among the organic sources, incorporation of subabul @ 5 t ha−1 recorded the highest number of total grains panicle−1, filled grains panicle−1, lowest number of unfilled grains panicle−1 and spikelet sterility in both the years. Among the fertilizer levels tested, 200:50 N:K2O kg ha−1 recorded the highest number of total grains panicle−1, filled grains panicle−1, while 150:75 N:K2O kg ha−1 recorded the lowest spikelet sterility. The highest spikelet sterility was recorded with the application of 225:0 N:K2O kg ha−1 in both the years. Interaction effect was found significant on total grains panicle−1 and filled grains panicle−1. Subabul incorporation @ 5 t ha−1 + 200:50 N:K2O kg ha−1 recorded the highest number of total and filled grains panicle−1 and was comparable to subabul incorporation @ 5 t ha−1 + 200:25 N:K2O kg ha−1.
Soil erosion and land degradation are led by frequent floods and droughts which are the prime reasons of low productivity in land areas. Poor soil conservation practices, lack of technology transfer, and low-yielding crop varieties are further degrading soil fertility status of land under rainfed farming. In general, crops grown on rainfed soils are highly prone to drought stress and multi-nutrient deficiencies, because these are coarse-textured soils of low water and nutrient retention capacity, low soil organic matter (SOM) content with less aggregate stability. Mono-cropping of staple crops and mining of essential nutrients from soil have caused nutrient imbalance and deterioration of soil quality. Degrading soils, accelerating soil erosion, depleting soil fertility, decreasing soil moisture-holding capacity, depleting ground water table, and increasing multiple nutrient deficiencies lead to low crop yields and perpetuate rural poverty.
The present investigation was carried out during 2009–2010 to monitor the changes in maturity indices i.e total organic carbon, total nitrogen, C/N ratio, humic substances and humification index during conventional method of composting and vermicomposting of different organic residues i.e sugarcane trash, weeds, vegetable market waste and paddy straw. The results revealed that the total organic carbon and C/N ratio decreased while total nitrogen and humic substances increased with the passage of time during composting in all the organic residues. Vegetable market waste recorded narrow C/N ratio with high total nitrogen content in both the composting methods. Where paddy straw recorded less nitrogen with wide C/N ratio. The highest humic substances were observed in vegetable market waste vermicompost followed by weed vermicompost. Minimum per cent of humic substances were recorded with cane trash and rice straw. A well known index for humification is the HA/FA ratio, in both the composts paddy straw compost recorded low ratio and high ratio was recorded in vegetable market waste compost. Thus, vermicomposting offers a promising solution for the recycling of organic wastes into valuable organic manure within a short period of time over conventional composting.
Studies on cumulative and residual effects of Integrated Nutrient Management of khraif rice on soil fertility status of rabi green gram was conducted at Regional Agricultural Research Station, Anakapalle during rabi 2009 and 2010. Results revealed that irrespective of the treatments, the organic carbon content observed under cumulative effects were higher than their corresponding residual treatments and the contents were higher in second year than first year. All the treatments meant for cumulative effects recorded higher available nutrient status than their corresponding residual treatments. The increase in mean available nitrogen, phosphorus and potassium contents after harvest of greengram due to cumulative effects was 5.6 & 5.18, 14.36 & 16, 4.14 & 4.3 % during 2009 and 2010, respectively. In case of micronutrients, the percent increase during 2009 and 2010 in cumulative effects over residual effects was, 5.1 & 11.54 (Zn), 2.6 & 5.45 (Fe), 9.5 and 10.1 (Cu) and 2 & 3.53 % (Mn), respectively. Among cumulative and residual effects, cumulative effects performed better and between two years build up was more in second year than first year. Among different treatments, the treatment which received 75 % recommended dose of chemical fertilizers + vegetable market waste @ 2.5 t ha-1 to kharif rice and 50 % chemical fertilizers to rabi greengram) recorded significantly higher available macro and micronutrient status and it was on par with 50 % chemical fertilizers+ vegetable market waste vermicompost @ 2.5 t ha-1 to kharif rice and 50 % recommended dose of chemical fertilizers to rabi greengram) and 75 % chemical fertilizers+weed vermicompost @ 2 t ha-1 to khraif rice and 50 % chemical fertilizers to rabi greengram). The treatment with 100 % chemical fertilizers to kharif rice and 50 % chemical fertilizers to rabi greengram recorded significantly lower available nutrient status, which was significantly lower than the integrated nutrient treatments, but was superior to absolute control.
Rainfed dryland agriculture has a significant role in providing food and nutritional security, in addition to contributing to many sustainable development goals (SDGs) of the world. Rainfed lands in India constitute about 55% of the total net sown area, of which about 48% of the area is for food crops and 68% of the area is for non-food crops, and they contribute to 21% of the country's GDP and provide 60% of the employment. The ecosystem features of rainfed agriculture vary from region to region across the world. Unfortunately, due to over exploitation, the quality of natural resources in rainfed areas is gradually declining. Ultimately, these areas are suffering from biophysical and socioeconomic constraints, which greatly affect the agricultural productivity. Deficient rainfall and improper distribution of rainfall, shallow soils, multi-nutrient deficiencies, poor soil organic carbon, and low soil biodiversity are major productivity constraints of rainfed drylands. This chapter highlights the production constraints of rainfed ecosystems, especially in India, by stressing soil-related problems and their management in order to improve agriculture productivity and soil health.
Sugarcane is important sugar crop which is accounting for approximately 80 percent of world sugar production. Sugarcane is one of the important agro industrial crops of commercial importance grown in North Coastal Andhra Pradesh, India. During processing of cane, sugar mills will discharge huge amounts of wastewater as large quantities of water is utilized in sugar mills. However, water resources are limited and a wide gap exists between available water supply and the amount of water required for intensive cropping, appropriate use of industrial effluents may be helpful in meeting a part of the increased water demand. No systematic study has been carried out so far to assess the relative heavy metals availability in soils irrigated with effluent waters. Therefore, a study was undertaken to survey both surface and subsurface soils irrigated with effluent waters for availability of heavy metals and also to assess the contents of the pollutant elements in sugar industrial effluents at the point of source. Survey of effluents and irrigation waters for their quality (heavy metal, RSC, SAR, pH and EC) with special reference to sugarcane cultivation in different factory zones of North Coastal Zone was carried out during 2011-12 and 2012-13.Effluents samples were collected from all the five existing sugar factory areas of North Coastal Andhra Pradesh viz., M/s Thummapala Cooperative sugar factory, Anakapalle, M/s Etikoppaka Cooperative sugar factory, Darlapudi and M/s Govada Cooperative sugar factory, Chodavaram of Visakhaptanm district; M/s GMR Sugar factory, Sankili of Srikakulam district and M/s NCS sugars, Bobbili of Vizianagaram district. Results revealed that all sugar factory effluents are highly acidic with the pH values varying from 4.32 (M/s Govada Cooperative sugar factory, Chodavaram) to 5.50 (M/s Etikoppaka Cooperative sugar factory, Darlapudi). However after effluent treatment, the pH values in all the factory areas were reached to safer limits. Concentrations of magnesium, calcium, sodium and sodium absorption ratios are within the limits in all the factory effluents. Heavy metals viz., cadmium and lead also not recorded in factory effluents, whereas cobalt, nickel and chromium are found in traces. Hence, effluents from all the sugar factories can be used safely for irrigation with respect to concentration of heavy metals in the sugar factory effluents. Data on soil analysis results revealed that, effluent irrigated soils are neutral in reaction with non-saline in conductivity. Mean organic carbon content pertaining to all the five factory soils was medium in range. Hence, it is found safe to irrigate soils with treated sugar factory effluents as of soil physico-chemical and chemical properties are at permissible limits and for sugarcane cultivation.
Studies on the effect of integrated nutrient management (INM) on kharif rice and cumulative and residual effects on rabi greengram were conducted during 2009 and 2010 at Regional Agricultural Research Station, Anakapalle. Kharif rice was grown with 10 treatments, consisting of INM practices, whereas rabi greengram was grown by dividing the plots into two, one receiving 50% recommended fertilizers and the other without any fertilizers. Available nutrient status and their uptake were higher with INM practices, specially when vegetable market waste vermicompost was applied. With continuous chemical farming, there was not much change in the soil nutrient status, nutrient uptake and yield in both the crops. However, a distinct decrease was noticed in all the values when crops were raised without any external supplementation of nutrients. The highest profitable treatment in both the crops was found to be 75% recommended dose of nitrogen + vegetable market waste vermicompost @ 2.5 t ha−1.
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