0 Views
G. NARAYANA SWAMY*, A.V. NAGAVANI, K. BHARGAVI, B. SAHADEVA REDDY, M.V. VIJAY SANKAR BABU AND V. UMAMAHESH
Agricultural Research Station, Acharya N.G. Ranga Agricultural University, Anantapur – 515 001, Andhra Pradesh.
A field experiments were conducted at Agricultural Research Station, Ananthapuramu during 2014 and 2015 kharif seasons to compare the yield and yield attributes under organics in conjunction with inorganics in rainfed alfisols with and without protective irrigations during long dry spells. The experiment was laid out in Randomized block design in two separate blocks with same treatments, one block is under purely rainfed and another block was given protective irrigation. The comparison was made among the supply of 100 per cent nitrogen through organics, 100 per cent through inorganics, 50 per cent organic and 50 per cent inorganic and with predominant sheep penning practice in the region under both rainfed and protective irrigated condi-tions. The results revealed that the crop yields increased from the 2014 to 2015 kharif under both the rainfed and protective irrigation conditions. But the magnitude of increase in the yield was more in protective irrigation as compared to the rainfed conditions. The study revealed that the organics in conjunction with inorganics significantly influenced the yield of groundnut under rainfed and protective irrigation conditions in alfisols of Andhra Pradesh. The greater response was observed for the application of organic manures and sheep penning under both rainfed and protective irrigation situations.
Organic, inorganic, sheep penning, rainfed, protective irrigation, groundnut yield.
The production and productivity of Groundnut (Arachis hypogaea L.) in rainfed alfisols of Andhra Pradesh is low as compared to the national average. The majority of the groundnut area is in the Anantapur and other districts of the rayalaseema region. The low productivity of kharif groundnut may be due to cultivation in marginal and sub marginal lands, little or no biomass recycling, low soil organic matter, sub optimal nutrient application, low nutrient use efficiency and multi nutrient deficiencies, coupled with frequent drought. There is a high variability in the onset of monsoon, very low and poor distribution of rainfall during growing season. The agro ecological region is complex, risk prone and under invested. Therefore, there is a need for regionally differentiated nutrient management strategies (Nataraj et al., 2016). Coupled with the above reasons, groundnut is an exhaustive crop and removes large amount of macro and micro nutrients from soil. None of the sources of nutrients can meet the total plant nutrient need of crop adequately. Hence integrated use of nutrients from
chemical and locally available organic sources is the most efficient way (Solanki et al., 2006). The integrated use of locally available organic sources not only supplies the nutrients but also improves the soil physical properties, enhances the soil fertility status and intern enhances the sustainability of the rainfed production system. Keeping this in view the present study was under taken to evaluate the efficacy of organics in conjunction with inorganics on yield of kharif groundnut under rainfed and protective irrigation conditions in alfisols of Andhra Pradesh.
Field experiments were conducted at Agricultural Research Station, Ananthapuramu during kharif, 2014 and 2015 in fixed plots for two consecutive seasons to study the efficacy of organics in conjunction with inorganics on yield of groundnut under rainfed and protective irrigation conditions. The soil type is alfisols and topography of the site is nearly level to gentle (1-3% slope). The experiment was laid out in completely randomized block design with three replications in two separate blocks viz., purely rainfed block and protective
irrigation block. Both block have eleven same treatments (Table 1 and 2) viz; T1: Control (no organics and inorganics), T2: Recommended dose of fertiliser (RDF) (20 kg N ha-1: 40 kg P2O5 ha-1: 40 kg K2O ha-1), T3: 50 % nitrogen through urea + 50 % nitrogen through FYM ,T4: 100% nitrogen through FYM, T5: 50% nitrogen through urea + 50% nitrogen through leaf compost, T6: 100% nitrogen through leaf compost, T7: 50% nitrogen through urea + 50% nitrogen through sheep manure, T8: 100% nitrogen through sheep manure,T9: 100 % nitrogen through sheep penning,T10: 100% nitrogen through enriched groundnut shells and T11: 50% nitrogen through urea + 50 % nitrogen through enriched groundnut shell. Prior to the experiment initial soil analysis (0-30 cm depth) was done in the laboratory using standard soil analytical procedures (Jackson, 1973). Organic manures were applied two weeks before sowing of the crop. Nitrogen, phosphorus and potassium were applied in the form of urea, diammonium phosphate and muriate of potash respectively at the time of sowing. In protective irrigation block, two irrigations were given at 55 and 75 DAS during 2014 and one irrigation at 75 DAS was given at 75 DAS during 2015 with 20 mm depth of water. Post-harvest soil samples were analyzed for different physico-chemical properties. The yield and yield attributes were recorded and compared with rainfed and protective irrigation block and also among the different sources of organics in conjunction with inorganics on yield of groundnut.
During both the years of experimentation the organics in conjunction with inorganics on yield of groundnut under rainfed and protective irrigation conditions in alfisols exerted marked influence on the number of filled pods plant-1 in groundnut (Table 1). The pod formation is the complex process and governed by complementary interaction between source and sink. Thus the favorable effect of readily available nutrients with 100 per cent nitrogen through sheep penning is evident with higher dry matter accumulation and effective translocation of photosynthates to the sink which in turn resulted in higher number of filled pods plant-1. Further, application of nutrients through FYM and fertilizers or recommended dose of fertilizers alone under rainfed conditions and leaf compost under protective irrigated condition was attributed to increased size of the source and consequently,
the enhanced partitioning of photosynthates towards newly formed sink. The results were in conformity with the findings of Reddy et al. (2010).
Under both the farming situations during two consecutive years of study, the number of ill filled pods plant-1 did not exhibit any significant difference among the treatments except control although the lowest number of ill filled pods plant-1 were recorded with 100 per cent nitrogen through sheep penning (Table 1). Control recorded the higher number of ill filled pods plant-1.
The higher hundred pod weight with the sheep penning treatments might be due to adequate supply of nutrients to the crop (Table 2). Further, sheep penning and FYM have also helped in improvement of soil physico chemical properties viz., aggregate stability and soil organic carbon content as well as moisture availability for better growth and development of the plant. Similar findings were also obtained by Kamalakannanan and Ravichandran (2013) and Ola et al. (2013).
During both the years of study, under rainfed condition, the highest kernel weight of groundnut was recorded with supply of 100 per cent nitrogen through sheep penning (Table 2). This might be due to improved soil fertility in terms of soil organic matter, soil biological population there by better availability and uptake of plant nutrients, which might have synergistic effect in maintaining the higher chlorophyll content, favorable enzyme activity and other biological process, enable higher out turn of photosynthates for production of bold seeds. Similar results were reported by Datta et al. (2014) and Patil et al. (2015). The lowest hundred kernel weight was recorded with control (T1) due to poor soil fertility status.
During both the years of study, the highest shelling percentage in groundnut was recorded with supply of 100 per cent of N through sheep penning (Table 2). This might be attributed to enhanced partition of photosynthates to the developing pods. Moreover, the higher hundred kernel weight with the above treatments might have resulted in higher shelling percentage. More number of bigger sized
pods plant-1 might have accommodated larger kernels providing sufficient space for development with balanced and adequate supply of nutrients. Similar observations were made by Datta et al. (2014) and Jena (2015).
Pod yield in groundnut was significantly influenced by combinations of organic and inorganic sources of nitrogen. During kharif, 2014 and 2015, the highest pod yield (842 and 1530 kg ha-1) of groundnut was recorded with supply of 100 per cent nitrogen through sheep penning (Table 3). Under protective irrigation during kharif 2014 and 2015, the same treatment recorded highest pod yield of 1280 and 2013 kg ha-1.
The beneficial effect of sheep penning, FYM in conjunction with fertilizers may be due to the effect of organic matter in improving the physical, chemical and biological environment of the soil conducive for better plant growth and thereby higher pod yield (Reddy et al. 2010). The slight increase in pod yield with recommended dose of fertilizes might be due to immediate availability of adequate quantity of NPK required for the crop growth and development (Devi et al., 2003). The pod yield being function of yield attributes which was favorably influenced by supply of 50 per cent nitrogen through organics and 50per cent through inorganics which might have led to the reduction of C: N ratio and stimulation of the mineralization process of organic nitrogen that might have intern resulted in greater accumulation of dry matter right from the early stage of the crop growth. The results were agreement with the findings of Patil et al. (2015).
of nitrogen through any source in control (T1) resulted in poor performance of the crop which could be noticed by the lowest values of all the growth parameters, yield attributes, nutrient uptake and pod yield. These results are in conformity with the findings of Shankaranarayana et al. (2004).
Based on the outcome of the investigation, it could be inferred that the efficacy of organic manures, particularly the sheep penning showed greater response and yielded better even under rainfed conditions. On the contrary, under protective irrigation during critical stage of the crop and also during long dry spells organic manures in conjunction with the inorganics given higher yield. This revealed that the organics in conjunction with inorganics significantly influences the yield of groundnut under rainfed and protective irrigation conditions in alfisols of Andhra Pradesh. This also suggested that the conjunction of organic and inorganic sources of nitrogen is necessary for sustainable production of groundnut in low rainfall areas of Andhra Pradesh.