Loading...
Dr. Rajendra Prasad Central Agricultural University, Pusa
In the imperial Gazetteer of India 1878, Pusa was recorded as a government estate of about 1350 acres in Darbhanba. It was acquired by East India Company for running a stud farm to supply better breed of horses mainly for the army. Frequent incidence of glanders disease (swelling of glands), mostly affecting the valuable imported bloodstock made the civil veterinary department to shift the entire stock out of Pusa. A British tobacco concern Beg Sutherland & co. got the estate on lease but it also left in 1897 abandoning the government estate of Pusa.
Lord Mayo, The Viceroy and Governor General, had been repeatedly trying to get through his proposal for setting up a directorate general of Agriculture that would take care of the soil and its productivity, formulate newer techniques of cultivation, improve the quality of seeds and livestock and also arrange for imparting agricultural education. The government of India had invited a British expert. Dr. J. A. Voelcker who had submitted as report on the development of Indian agriculture. As a follow-up action, three experts in different fields were appointed for the first time during 1885 to 1895 namely, agricultural chemist (Dr. J. W. Leafer), cryptogamic botanist (Dr. R. A. Butler) and entomologist (Dr. H. Maxwell Lefroy) with headquarters at Dehradun (U.P.) in the forest Research Institute complex.
Surprisingly, until now Pusa, which was destined to become the centre of agricultural revolution in the country, was lying as before an abandoned government estate. In 1898. Lord Curzon took over as the viceroy. A widely traveled person and an administrator, he salvaged out the earlier proposal and got London’s approval for the appointment of the inspector General of Agriculture to which the first incumbent Mr. J. Mollison (Dy. Director of Agriculture, Bombay) joined in 1901 with headquarters at Nagpur
The then government of Bengal had mooted in 1902 a proposal to the centre for setting up a model cattle farm for improving the dilapidated condition of the livestock at Pusa estate where plenty of land, water and feed would be available, and with Mr. Mollison’s support this was accepted in principle. Around Pusa, there were many British planters and also an indigo research centre Dalsing Sarai (near Pusa). Mr. Mollison’s visits to this mini British kingdom and his strong recommendations. In favour of Pusa as the most ideal place for the Bengal government project obviously caught the attention for the viceroy.
Browse
12 results
Search Results
ThesisItem Open Access Effect of nano urea on soil nitrogen status, uptake, yield and juice quality of Sugarcane in calcareous soil of Bihar(RPCAU, Pusa, 2023) Mallick, Jidan Ali; Thakur, S.K.The use of nano-fertilizers in agriculture is expanding quickly as a strategy to increase crop yields, nutrient use efficiency and decrease the use of synthetic fertilizers. A novel agricultural input developed through nano technology is called nano urea which provides nitrogen to plants.Nano urea which contains 4% N by weight in nano form. Its use efficiency is higher than that of regular urea and most crops can be benefited from nano urea as a source of nitrogen. A field experiment was therefore, conducted in 2022–2023 at the Crop Research farm Kalyanpur, Dr. Rajendra Prasad Central Agricultural University, Bihar, with an objective to study the “Effect of nano urea on soil nitrogen status, uptake, yield and juice quality of Sugarcane in calcareous soil of Bihar”.The experiment was carried out in RBD design with 10 treatmentswith three replications comprising control, application of nitrogen @ 50, 75 &100 %recommended dose alone or in combination with spray of nano urea (NU) @ 1.0 &2.0% at tillering & grand growth stages. Spray of nano urea @ 2.5% was carried out only at tillering stage. The results revealed that the number of tillers increased significantly from 44.59 - 97.30×103 ha-1 and 62.36 - 110.53× 103 ha-1 at 90 and 120 days after planting with increasing levels of nitrogen. Significant increase in the number of millable cane (67.84 - 76.72 ×103 ha-1) over control was observed due to addition of different doses of nanourea. Applying nano urea had a positive effect on cane yield (61.24 to 79.24 t ha-1) and sugar yield (7.36 to 9.92 t ha-1) but highest cane and sugar yield (81.95 t ha-1 and 10.23 t ha-1 respectively) was observed due to application of recommended dose of nitrogen (RDN). The application of different doses of nano urea did not show significant variation in plant height, cane length, cane girth but single cane weight varied significantly (0.719-1.024 kg) across the different treatments. The application of nano urea in various combinations did not result in statistically significant improvements in cane juice quality parameters like brix, pol, purity, and commercial cane sugar. The highest available nitrogen content (246.14 kg ha-1) was observed in treatment received 100% recommended dose of nitrogen. The available nitrogen content in post-harvest soil varied 224.40 to 236.53 kg ha-1 due to application of nano urea @ 1.0, 2.0 & 2.5% along with 50% and 75% nitrogen fertilizer. Nano urea had no notable impact on the available phosphorus and potassium content of the post-harvest soil. The meanuptake of nitrogen (88.07 to 279.53 kg ha-1), phosphorus (12.4 to 15.36 kg ha-1) and potassium (113.07 to 154.75 kg ha-1) by sugarcane crop varied significantly across the treatments. The benefit-cost ratio in the treatments receiving 75% RDN along with spray of NU @ 1.0, 2.0 and 2.5% were found at par with the maximum BC ratio (1.89) observed in treatment receiving 100% RDN. Thus,application of 1% nano urea at tillering and grand growth stage along with 75% RDN may be used for sugarcane production in calcareous soil of Bihar.ThesisItem Open Access Impact of residue incorporation and zinc fertilization on soil health and micronutrient contents of rice grain(RPCAU, Pusa, 2023) PRIYADARSHANI, CHITRA; Laik, RanjanThe major goals of researchers under intensive cropping systems, especially in Asian countries, where demand for food is very high due to population pressure, is to achieve higher productivity, better quality produce and sustenance of soil health. Hence, a study on long term crop residue incorporation (29 years) and zinc fertilization effects was done to understand how these practices synergistically enhance soil health, rice productivity and nutritional quality of rice grain under rice-wheat cropping system. This research was conducted in a potentially Zn deficient calcareous soil at RPCAU research farm in a Split Plot Design (SPD) with different crop residue levels at 0%, 25%, 50%, and 100% in the main plot and varying Zn levels at 0, 2.5, 5.0, and 10.0 kg ha-1 in the sub-plot. Zinc was administered at the different levels initially at the commencement of the study and subsequently reapplied after a span of 25 years (during 2018). On the other hand, crop residue was incorporated into the soil every year following the harvest of each crop. Combining complete crop residue incorporation with residual 10 kg Zn ha-1 boosts soil organic carbon, available nitrogen, and overall soil health, benefiting aggregation, water retention, and nutrient availability. Long-term incorporation leads to higher rice yields, improved grain protein, zinc and iron content, correlating positively with enhanced soil health determined by PCA analysis, except for available B, Cu, and Mn.ThesisItem Open Access Effect of NPK, FYM and Zn application on transformation of Zn, biological properties and nutrient availability under rice-wheat cropping system in calcareous soil(RPCAU, Pusa, 2023) KACHHAP, AANCHAL; Kumar, VipinThe present study aimed to investigate the effect of NPK, FYM, and Zn application within a RWCS in calcareous soil on various aspects, including yield, nutrient uptake, chemical properties, and biological characteristics of post-harvest soil of second wheat crop in the year 2023. Additionally, the study examined different fractions of zinc in the soil and their correlations with each other, as well as with yield, nutrient uptake, and available zinc content. The research was conducted as a field experiment that commenced during the kharif season of 2021 at the Pusa Research Farm of RPCAU Samastipur, Bihar. The experimental layout followed a randomized block design comprising ten treatments replicated three times. These treatments included a range of conditions: T1 as the absolute control, T2 with RDF (Recommended Dose of Fertilizers), T3 with RDF and FYM @ 5 t ha-1, T4 with RDF and foliar spray of 0.5% ZnSO4, T5 with RDF and 5 kg Zn ha-1, T6 with RDF and Geoxol.com @ 40 kg ha-1, and T7, T8, T9, T10 similar to T2, T3, T4, T5, respectively, but with an increased RDF level of 125%. Among these treatments, T10 (125% RDF + 5 kg Zn ha-1) exhibited the highest yield of 5.21 t ha-1 and 4.64 t ha-1 with grain yield response of about 6.3 to 27.1 and 0.21 to 0.90 per cent in rice and wheat crop respectively. However, when considering nutrient uptake, T8 (125% RDF + FYM @5 t ha-1) showed the greatest total nutrient uptake, and it was statistically similar to treatments involving increased fertility levels in combination with organic supplementation and zinc sources. Remarkably, substantial nutrient availability (N, P, K, S, and Zn) was detected in treatments with enhanced fertility levels, both independently and in various combinations. Moreover, treatment T8 demonstrated noteworthy dominance in biological properties, indicating that FYM and higher fertilizer levels played a pivotal role in stimulating microbial growth. This heightened response was most pronounced in treatments involving 125% RDF, either alone or in combination, mainly due to the initial nutrient deficiency of the soil. Analyzing different zinc fractions in the post-harvest soil indicated that the water-soluble and exchangeable forms were minimal, while the residual form was predominant revealing that the majority of total zinc resided in the residual form. Interestingly, positive and significant correlations were observed among yield, nutrient uptake, and available zinc content. The order of dominance of different zinc fractions in the soil was: Residual-Zn > Organically bound-Zn > Zn bound to crystalline oxide > Zn bound to amorphous oxide > Complexed-Zn > Water soluble plus exchangeable-Zn. These findings inform agricultural practices and soil management strategies to farmers by emphasizing the benefits of balanced NPK fertilization with organic supplementation and zinc for improved crop yields. They underscore the importance of addressing micronutrient deficiencies, particularly zinc, and highlight the role of organic matter in enhancing soil health. Additionally, the study offers insights into nutrient build-up and zinc distribution, guiding more efficient soil fertility strategies. Overall, these findings promote a holistic approach to soil and nutrient management, enhancing sustainability in agriculture.ThesisItem Open Access Development of Targeted Yield Equations for Aerobic Rice (Var. Rajendra neelam) under Integrated Nutrient Management(Dr.RPCAU, Pusa, 2022) KUMAR, NARESH; SUMAN, S. N.Field experiment was conducted at Pusa farm, RPCAU during the year 2021 to generate Targeted Yield based Fertilizer prescription equations for aerobic rice Var. Rajendra neelam under integrated nutrient management system. In order to develop fertilizer prescription equations, complex experiment of rice was conducted at nursery jhilly field with aerobic rice (cv. Rajendra neelam) by superimposing 24 treatments consisting of four levels of N (0, 60,120 and180 kg/ha), four levels of P2O5 (0, 30, 60 and 90 kg/ha), four levels K2O (0, 20, 40 and 60 kg/ha) and three level of vermicompost (0, 1 and 2 t/ha). The integrated nutrient management approach had a positive impact on organic carbon, soil available nutrient status, crop yield, and nutrient uptake by aerobic rice. When compared to other treatments, a combined application of 120 kg nitrogen, 60 kg phosphorus, and 40 kg potassium per hectare, along with 2 t/ha vermicompost resulted in the highest available NPK in soils with the highest crop yield and nitrogen, phosphorus and potassium uptake by aerobic rice. Fertilizer prescription equations were formulated for aerobic rice by following Ramamurthy’s Inductive-cum-targeted yield approach. Based on the experiment in the nutrient requirement (NR) for producing one quintal of aerobic rice was found to be 4.09, 0.90, 2.16 kg/q with respect to N,P and K respectively. The NPK contributions to aerobic rice from fertilizers were 48.11, 38.74, and 58.46 % respectively. Conversely, the percentage contribution of NPK from organic component that is organic efficiency was 7.34%, 4.25 %, 5.3%. Based on NR, CS, CF and CO the fertilizer prescription equations were developed for aerobic rice variety (Rajendra neelam) and an estimate of fertilizer dose were formulated in the form of ready reckoner for a range of soil test values and desired yield targets.ThesisItem Open Access EFFECT OF INTEGRATED NUTRIENT MANAGEMENT ON PRODUCTIVITY AND QUALITY OF SUGARCANE IN CALCAREOUS SOIL(Dr.RPCAU, Pusa, 2022) KUMAR, BRAJESH; Sinha, S.K.At Dr. Rajendra Prasad Central Agricultural University in Bihar, a field experiment was carried out to investigate the “Effect of integrated nutrient management on productivity and quality of sugarcane in calcareous soil” during 2021–2022.Vermicompost, green manuring (green gram), fertilizer-NPK (150:85:60) and biofertilizer (Azotobacter and PSB) were used as part of the treatments. The vermicompost was applied at planting and green gram was applied 60 days after planting (DAP). During the spring, sugarcane crop (cv. CoP 112 early) was planted. The germination percent was found non-significant and it varied from 36.5-43.4% and 46.5-55.5% at 45 and 60 days after planting respectively. Compared to strict control and 100% RDF, the combined application of organic, inorganic and biofertilizer produced a much higher number of tillers. The dry matter accumulation at 90,120 and 150 days after planting was found significant while at harvest stage it was found nonsignificant. The number of millable canes varied significantly and ranged from 70.5 × 103 to 125.4 × 103 ha-1. The maximum NMC (Number of millable cane) was obtained in the treatment receiving RDF together with vermicompost and biofertilizer (Azotobacter and PSB). Due to different treatments, the mean cane yield varied significantly and ranged from 41.8 to 94.0 t ha-1. The treatment group receiving RDF coupled with vermicompost and biofertilizer had the highest cane yield, whereas the group receiving absolute control (no fertilizer) had the lowest. Sugar yield is a function of cane yield and followed a similar trend to cane yield. The mean sugar yield varied significantly from 4.5 - 10.5 t ha-1. Brix, pol, purity coefficient and commercial cane sugar was found non-significant. The soil available N (224.33 - 278.92 kg ha-1), available P (22.28 - 36.33 kg ha-1), available K (124.67 - 165.20 kg ha-1) and available S (12.64 - 19.21 mg kg-1) varied significantly due to application of integrated nutrient management in soil. The use of organic and inorganic fertiliser sources over absolute control was also noted as a considerable increase in the Fe, Zn, Cu and Mn content of post-harvest soil. The soil organic carbon stock was found to be non-significant due to the application of nutrients from organic and inorganic fertiliser while the mean soil organic carbon (0.48 - 0.56%), soil microbial biomass carbon (129.10 - 255.90 mg kg-1), and CO2 evolution (36.83 - 60.70 mg 100g-1 soil 24 hr-1) varied significantly. The microflora population in post-harvest soil was significantly higher in treatment receiving RDF along with vermicompost and biofertilizer (Azotobacter and PSB). Due to the impact of various nutrient combinations, the absorption of N (126.97 - 292.58kg ha-1), P (12.54 - 29.96 kg ha-1), and K (114.43 - 271.43kg ha-1) varied significantly. The trend of cane output was similar to the intake of minerals. The effect of various treatment on agronomic use efficiency and physiological use efficiency was varied significantly.ThesisItem Open Access Impact of intensive fertilizer use on soil health under maize based cropping system(Dr.RPCAU, Pusa, 2022) KANDARI, ABHISHEK SINGH; Tiwari, SanjayA study was conducted in the block Khodawandpur (Begusarai) among farmers taking different cropping system (rice-maize, pigeon pea-maize, soybean-maize, maize-wheat and rice-wheat) to study the influence of fertilizer application on soil health. Several soil quality parameters were assessed during the experiment to assess the influence of five cropping systems on soil quality and then it was correlated with the yield of crops in different cropping system. The soil pH variations ranged from 8.01 to 8.26 at the surface layer (0-15cm) and from 8.18 to 8.32 at the sub surface layer (15-30cm). The rice-wheat cropping system had the lowest soil pH (8.01), followed by the rice-maize and pigeon pea-maize cropping system, which might be ascribed to soil submergence during rice cultivation and a higher amount of leaf litter falling over the field throughout crop life of the latter cycle. The range of electrical conductivity variations was determined to be 0.30 to 0.40 dS m-1. The low salt content observed in the pigeon pea cropping system at both soil layers exhibited greater variability than other cropping system. The pigeon pea cropping system has the highest organic carbon content (0.46%), followed by soybean-maize (0.41%) cropping system. The addition of organic carbon and the application of varied doses of inorganic fertilizers caused significant differences in soil available nitrogen in this study under different cropping systems. Nitrogen availability ranged from 137.98 to 178.12 kg ha-1. The maximum quantity of available nitrogen was reported in the pigeon pea cropping system might be attributed to plant biomass deposition and biological nitrogen fixing. Available phosphorus status in soil varied from 31.71 to 44.50 kg ha-1 and it followed the order: pigeon pea-maize>soybean-maize> maize-wheat> rice-wheat> rice-maize. At the surface soil layer, pigeon pea-maize cropping system had the highest soil available potassium (188.84 kg ha-1) and rice-maize cropping system had the lowest (148.24 kg ha-1). Micronutrients varied less in the cropping system. DTPA extractable Fe levels were found to be high in all the cropping systems. DTPA extractable Cu and DTPA extractable Mn were found to be higher in rice-wheat cropping systems, with mean values of 1.93 mg kg-1 and 4.87 mg kg-1, respectively. The large range in Zn concentration in surface soil (0-15cm) was observed under various farming systems. The highest levels of DTPA extractable Zn were found in pigeon pea-maize cropping systems (0.83 mg kg-1). Farmer’s fertilizer and other management techniques may be the reason behind Zn deficiency in soil. The bulk density of the pigeon pea-maize cropping system was found to be lowest (1.37 Mg m-3), whereas rice-wheat had the highest bulk density with a mean value of 1.41 Mg m-3.There was less variation in bulk density among all the cropping system. Relatively high density values were detected in the subsurface layer. Data from several cropping systems revealed that almost all the cropping systems had lower mean values of maximum water holding capacity attributed to intensive tillage and other cultural practices used by farmers. The top layer of a pigeon pea-maize cropping system had the maximum water holding capacity (32.04%), whereas the sub-surface layer of the same cropping system had 28.55%.. Water stable aggregates ranged between 23.23% to 31.03%. The pigeon pea-maize cropping system resulted in the highest mean values (31.03%), whereas the rice-maize cropping system was found to have lowest values (23.23%). Subsurface layer values were found to be lower than surface layer. Soil respiration was highest in the pigeon pea-maize cropping system (1.10 mg CO2 g-1) and lowest in the rice-maize cropping system (0.69 mg CO2 g-1). Organic material was not included during cultural activities in the majority of the farmer’s field resulting in lower soil biological parameters. Cropping systems had active C levels ranging from 169.20 mg kg-1 to 207.93 mg kg-1. In 0-15cm soil depth, the pigeon pea cropping system had the highest mean value, whereas the rice maize cropping system had the least. The dehydrogenase and fluorescein diacetate in the top surface layer ranged from 70.92 to 84.30 (μg TPF g-1 24 h-1) and 2.64 to 4.17 (μg Fluorescein g-1 soil hr-1). Legume based cropping system had the highest dehydrogenase and fluorescein diacetate in the soils of the cropping systems, while rice-maize had the least. The low quantities of dehydrogenase and fluorescein diacetate enzymes found in rice-maize might be linked to low organic carbon content and poor agricultural techniques. Yield of the crops under different cropping system was found to be significantly and positively correlated with most of the soil health parameters but in case of bulk density it was found to be negatively correlated.ThesisItem Open Access Impact of sugarcane cultivation on soil carbon pools and soil health in Samastipur district of Bihar(DRPCAU, PUSA, 2022) KUDI, BABITA; MEENA, SUNITA KUMARIA Study entitled “Impact of sugarcane cultivation on soil carbon pools and soil health in Samastipur district of Bihar’’ was carried out at Department of Soil Science, Dr. Rajendra Prasad Central Agricultural University, Pusa, Samastipur, Bihar with the objective to establish the relationship between soil carbon pools and soil health parameters. Soil samples were analyzed in the laboratory for different physical, chemical and biological properties by Cornell Soil Health Laboratory Comprehensive Assessment of Soil Health (CASH) standard operating procedures. Sugarcane is a long duration, heavy feeder and nutrient exhaustive crop. The excessive and imbalanced use of chemical fertilizer has deterioration of soil health. The soil organic carbon content is continuously declining due to the non-addition of organic matter and to continuous cultivation of sugarcane crop which is extensive in nature. Restoration of organic matter is thus, needed for maintaining soil health and improving productivity through breakdown of continuous cultivation of sugarcane and the addition of organic amendments. A wide variation was observed for soil quality parameters which included pH mean value was 8.35±0.14 in 0-15 cm soil depth and 8.20±0.15 in 15-30 cm; electrical conductivity (EC) mean 0.59±0.18 dS m-1 in 0-15 cm and 0.48 ± 0.18 dS m-1 in 15 - 30 cm; bulk density (BD) mean 1.49 ± 0.10 g cm-3 in 0-15 cm and 1.58±0.08 g cm-3 in 15-30 cm; Wet Aggregate Stability (WAS) mean 26.9±6.6 % in 0-15 cm and 24.67±9.93 % in 15-30 cm. Among the major soil nutrients, the mean value of available N was 192±14 kg ha-1 in 0-15 cm and 187±14 kg ha-1 in 15-30 cm; mean value of available P2O5 was 29.2±5.4 kg ha-1 in 0-15 cm and 25.8±5.2 kg ha-1 in 15-30 cm soil depth; mean value of available K2O was 161±24 kg ha-1 in 0-15 cm and 154±24 kg ha-1 in 15-30 cm soil depth and available S was 8.52±1.40 mg kg-1 at 0-15 cm and 7.30±1.38 mg kg-1 in 15-30 cm soil depth. The variation in available soil micronutrients were as follows: Zn mean value was 0.57 ± 0.21 mg kg-1 in 0- 15 cm and 0.44 ± 0.22 mg kg-1 in 15-30 cm soil depth; Cu mean value was 1.24±0.58 mg kg-1 in 0-15 cm and 1.11±0.59 mg kg-1 in 15-30 cm soil depth; Fe mean value was 9.83±2.58 mg kg-1 in 0-15 cm soil and 8.44±2.52 mg kg-1 in 15-30 cm soil depth; Mn average value was 4.50±0.93 mg kg-1 in 0-15 cm soil and 3.36±0.89 mg kg-1 in 15-30 cm soil depth. Among the soil biological properties, soil protein (autoclaved citrate extractable protein), soil respiration, dehydrogenase activity and MBC mean values were 1.59±0.55 g kg-1, 0.72 ± 0.22 mg CO2 g-1 96 hrs-1, 4.86 ± 0.78 μg TPF hr-1 g-1, 113±15 mg kg-1in 0-15 cm soil and 1.19 ± 0.55 g kg-1 ,0.58 ± 0.23 mg CO2 g-1 96 hrs-1 , 3.59 ± 0.80 μg TPF hr-1 g-1 , 96.63 ± 16.90 mg kg-1in 15-30 cm soil respectively. The mean value of different soil carbon pools were as follows: Walkley-Black carbon was 5.23±1.06 g kg -1 in 0-15 cm soil and 4.56±0.96 g kg -1 in 15-30 cm soil; total organic carbon was 7.64 ± 1.20 g kg-1 in 0-15 cm soil and 7.10±1.49 g kg-1 in 15-30 cm soil; KMNO4 –C was 263±55 mg kg-1 in 0-15 cm soil and 235±54 mg kg-1 in 15-30 cm soil. Percent contribution of different SOC pools to the total SOC followed as: Non labile (32%) > Less labile (28%) > Very Labile (20%) > labile (19.7%) in 0-15 cm of soil and Non labile (35.6%) > Less labile (28.6 %) >Very Labile (18.6%) > labile (17.1%) in 15-30 cm depth of soil. Correlation coefficient of oxidisable organic carbon (0-15 cm soil) with various fractions of carbon and soil biological parameters ranged from 0.846 to 0.974. For 15-30 cm soil depth, correlation coefficient of OC was found significantly positive with TOC (0.925) and VL-C, L-C, LL-C (0.875, 0.899, 0.924, respectively). Therefore, it was recommended that the inclusion of other crops in a crop rotation leads to a build-up of active fractions of carbon, thus the biological activity that will support soil sustainability.ThesisItem Open Access RESPONSE OF INTEGRATED NUTRIENT MANAGEMENT ON ACTIVE POOLS OF SOIL ORGANIC CARBON AND BIOLOGICAL ACTIVITIES UNDER RICE BASED CROPPING SYSTEM(DRPCAU, PUSA, 2022) SHAI, SOURAV; SINGH, PANKAJBeing the backbone of India's food security, the Rice-wheat cropping system is the most profitable and prevailing cropping system in the Indo-Gangetic region, but recently it experienced significant decline in productivity because of depletion in soil organic matter due to low inputs of bio-resources and intensive crop rotation, depletion of soil fertility due to imbalanced use of chemicals and poor residue management leading to its burning. Residue management is a rising concern for better sustainability of Indian agriculture and environmental protection. Intensive cropping systems, lack of traditional use of agricultural crop residues, and lack of buyers of rice is pushing the farmers to opt for residue burning, which causes huge air pollution and global warming. To mitigate such problems IARI introduced a bio-decomposer method known as "Pusa Decomposer" to accelerate the decomposition of paddy straw in the field. Thus, with such background the present study entitled “Response of integrated nutrient management on active pools of soil organic carbon and biological activities under rice based cropping system” was conducted in kharif 2021 and Rice was the test crop at research farm of RPCAU, Pusa, Bihar. The present experiment is third cropping cycle that is kharif 2021 and it was carried out in randomized block design with nine different treatments and each of the treatments were replicated thrice in 3m x 4m plots. The treatments were T1 (100% RDF); T2 (50% N from Residue + 50% RDF); T3 (50% N from Residue + 50% RDF + Pusa Decomposer); T4 (50% N from Residue + 50% N from Green Manure); T5 (50% N from Residue + 50% N from Green Manure + Pusa Decomposer); T6 (Residue @ 2.5 tonnes ac-1 + Pusa Decomposer); T7 (Residue @ 2.5 tonnes ac-1) and T8 (Absolute Control). Bulk density and water holding capacity showed non-significant difference among different treatments under study and similarly, soil pH and EC had no significant impact due to integration of different nutrient sources. However available nutrients in soil had significant effect. Application of fertilizer solely or its integration with CR and/or PD showed a significant increase in available N, P and K, but crop residue incorporation failed to increase available N and P significantly as compared to control treatment whereas, integrated application of GM and CR significantly increased N & P as compared to control. On the other hand available K was significantly increased under residue incorporation i.e., in T6 and T7 compared to absolute control. Active carbon fractions like very labile and labile pools of carbon, Water-soluble organic carbon (WSC), microbial biomass carbon (MBC), acid hydrolysable carbohydrate (AHC) and soil respiration decreased with increase in the depth and all of them recorded higher value in the integrated treatments T3 and T5 and lowest value in absolute control (T8). It was observed that application of Pusa decomposer (PD) both in treatment T3 and T5 recorded increase in active carbon pools as compared to the corresponding treatments viz. T2 and T4 respectively only in surface soil (0-5cm). Grain and straw yield and yield attributing characters like number of panicles per hill, number of filled grains per panicle recorded higher values in treatment T1. The treatment T2 and T3 were found to be statistically at par with T1 whereas, absolute control (T8) showed the lowest values which did not differ statistically with treatments T7 and T6 while, GM addition with CR in treatments T4 and T5 recorded significant increase in grain yield and yield attributes as compared to absolute control. The INM treatments did not significantly affect test weight and harvest index of rice. Plant height of rice during flowering stage and harvesting stage was maximum under treatment T1 (100% RDF) followed by T3 and T2. These treatments show significantly higher plant height as compared to organically treated plots and rest of the treatments i.e., T4 to T8 were statistically at par. Days to 50% flowering recorded non-significant difference among different treatments. The enzymatic activities indicated that the microbial activity in soil, recorded higher values on integration of 50% N from Residue with 50% RDF and Pusa Decomposer (T3) and in treatment T5 with 50% N from Residue + 50% N from Green Manure + Pusa Decomposer (T5) which were found to be significantly higher than T2 and T4 respectively. The research findings indicate that the maximum benefits in terms soil quality or productivity was obtained under integration of 50% fertilizer, crop residue with pusa decomposer i.e. T3 which suggest the replacement of 50% fertilizer with crop residue incorporation and pusa decomposer not only increase yield but also improve soil health which is needed for the development of sustainable systems.ThesisItem Open Access INTERACTIVE EFFECT OF ZINC AND CROP RESIDUE ON SOIL BIOLOGICAL HEALTH IN A LONG TERM EXPERIMENT IN CALCAREOUS SOIL(DRPCAU, PUSA, 2022) PRADHAN, BOBBY; Singh, HemlataThe primary key to determining whether a system, like the rice-wheat cropping system is sustainable is through conducting a long-term experiment. Recently, a variety of factors, primarily the burning of crop residues have raised concerns about the sustainability of this system. In addition to that the increasing deficiency of zinc in calcareous soils has led to a decrease in overall crop yields. In this light, a long term field experiment was started under AICRP on “Microsecondary and pollutant elements in plants and soils” in Zn deficient calcareous soil at RPCAU Research Farm, Pusa in a split plot design with main plot divided into four crop residue levels @ 0, 25, 50 and 100% and sub plots into four levels of Zn @ 0, 2.5, 5.0 and 10 kg Zn ha-1 under rice- wheat cropping system. While Zn was applied as a starter dose at the beginning of the experiment and then again after 25 years, crop residue was incorporated following harvest of each crop. The yield of 28th rice crop was recorded and the post-harvest soil samples were used for the evaluation of biological parameters such as soil enzymatic activities (dehydrogenase, phosphatase, urease and glucosidase), soil microbial biomass carbon, soil respiration, chemical parameters such as pH, EC, available nutrients and nutrient uptake in rice grain and straw was also calculated. The activities of all the studied enzymes viz. dehydrogenase , phosphatase, glucosidase and urease were found to be highest with the application of 100% crop residue incorporation and 5 kg Zn ha-1 and was at par with the application of 10 kg Zn ha-1. Soil microbial biomass carbon and soil respiration were highest under 100% crop residue incorporated plots. The total uptake of nutrients viz. N, P, K, Zn by rice crop and post-harvest soil nutrient status were significantly improved with 100% crop residue application. A highly positive correlation between soil enzyme activities, yield and nutrient uptake was also obtained suggesting the positive role of crop residue incorporation in soil. The incorporation of 100% crop residues in combination with 10 kg Zn ha-1 recorded the highest overall rice grain and straw yield followed by 100% incorporation of crop residues with 5 kg Zn ha-1.
