Phosphorus (P) deficiency in soil limits crop yields and can be managed by P fertilizers. But mere applying P fertilizers alone may not be effective in justifying its bioavailability. At present global P reserves are declining in an increasing way which urges us to find out alternatives. Thus, the present work was taken to prepare phosphocompost using water hyacinth (Eichhornia crassipes) as feedstock, termite, and normal soil as bulking agents cum decomposers and enriched with single super phosphate. The effect of phosphocompost on rice(var.ADT-43) productivity, P availability and uptake was evaluated by comparing various P fertilizers (single super phosphate, rock phosphate, di-ammonium phosphate, nano phosphate) combined with or without phosphate solubilizing bacteria (PSB). The experiment was laid out in a completely randomized design with seven treatments including absolute control and replicated thrice. Phosphocompost produced with water hyacinth and termite soil microbes come with superior quality and early maturity compared to normal soil. Pot culture study results revealed that rice growth, yield, P availability and uptake were significantly (p<0.05) higher with SSP + PSB, and Nano phosphate +PSB treated plants, followed by Phosphocompost + PSB. The cost of P fertilizer (Rs/ha) related to yield (kg/ha) was found to be significantly low with phosphocompost (Rs.1132/-) than SSP (Rs.1530/-) and Nano P (Rs.2518/-). Further, phosphocompost combined PSB helps in optimizing the P availability in a long run through P solubilization thus sustained the P uptake. The present investigation brings light to the valorization of water hyacinth as compost will be an effective and economically viable alternative for P fertilizers.

Field experiments were conducted during the Kharif and rabi season of 2021 in the farmer’s field of Perampattu Village, Tirupattur Taluk & District, TN, India to study the effect of K and S management in groundnut. The soil of the experiment field belongs to sandy clay loam, available nitrogen (133.4 kg ha-1), phosphorus (16.8 kg ha-1), potassium (113.1 kg ha-1), and sulfur (4.80 mg kg-1), respectively. The experiments were laid out in Randomized Block Design (RBD) with eight treatments viz., T1-Control, T2–RDF (Blanket Recommendation as 25:50:75 kg NPK ha-1), T3- RDF + Add 0.25% of K through MOP (Foliar Application), T4– RDF + Add 0.5% of K through MOP (Foliar Application), T5– RDF + Add 0.25% of K through SOP (Foliar Application), T6– RDF + Add 0.5% of K through SOP (Foliar Application), T7– RDF + Add 0.25% of K through KNO3 (Foliar Application), T8– RDF + Add 0.5% of K through KNO3 (Foliar Application) and replicated thrice. Higher yield of groundnut in Kharif & rabi 3103 Kg ha-1 & 2895 Kg ha-1, respectively, and percent of yield increase in T4 was 3.9 and 5.63 over other treatments and also maximum gross income, net income, and benefit-cost ratio were obtained in RDF + Add 0.5% of K through MOP (T4) applied treatment in both seasons. The lowest gross income, net income, and benefit-cost ratio were achieved in T1.

Aim: To find out the CH4 and CO2 emission pattern and the considerable amount of SOC sequestered by using different organic sources in sandy clay loam soil. Study Design: Randomized Block Design. Place and Duration of the Study: The study was conducted in a farmer's field at Ayanathur, which is geographically located at 11°23’N latitude, 79°29'E longitude, and an altitude of +26 m MSL. Duration of the study confined to 2 years cycle from September 2016 to January 2018 I and II crops respectively. Methodology: Different sources of organic manures viz., Farm Yard Manure @ 12.5 t ha-1, vermicompost, pressmud, poultry manure, and composted coirpith are each @ 5 t ha-1 were applied as basally and incorporated along with Azospirillum and phosphobacteria @ 2 kg ha-1 as a soil application at the time of last ploughing. Fertilizers were applied as per the treatment  schedule of 150:50:50 kg N, P, and K ha-1 was followed throughout the period of study through urea, Di Ammonium phosphate and muriate of potash for rice crops. An open path LICOR analyzer 7700 and 7500 for CH4 and CO2 to find the CH4 and CO2 fluxes during the period of study through calibration of eddy covariance fluxes emissions were calculated. Results: Combined application of a Recommended dose of fertilizers along with Farmyard manure @ 12.5 t ha-1 reduced the CH4 emission by 13.6 and 15 % over other organic sources in rice whereas, the CO2 emission by 54.4 and 53.8% and 61.5 and 53.9 % over other organic sources in rice and sunflower respectively. Concomitantly, the SOC increased by 6.8 and 7.5% in rice and 4,7 and 4.4% in sunflower over other organic sources.