Search

Precision application of nutrient based on soil test value is important for improving nutrient use efficiency and yield of hybrid castor. Field trial was conducted during 2021 at Tapioca and Castor Research Station, Yethapur, Salem District, Tamil Nadu, India (110 ∘ 35' N, 780 ∘ 29' E). Fertilizer prescription equations (FPEs) were developed for hybrid castor by adopting inductive cum targeted yield model approach under irrigated condition on Alfisol. Initially, soil fertility gradients were established with respect to soil available N, P and K nutrients, and 24 treatments were imposed in three fertility strips under factorial randomized design. Principle component analysis revealed that all the variables accounted for developing the FPEs of hybrid castor are present at the positive quadrant which mean that all the variables are highly important toward the castor seed yield production. From the field experimental data, the basic parameters [nutrient requirement (NR) and nutrients contributions from farmyard manure (Co), fertilizer (Cf), and soil (Cs)] were computed. The nutrient required for producing one quintal of hybrid castor seed yield was evaluated as 3.20 kg of nitrogen, 1.23 kg of phosphorus pentoxide (P2O5), and 3.28 kg of potassium oxide (K2O). The study revealed that soil nutrient contribution was high in case of available phosphorus (41.87%), available nitrogen (21.56%), and available potassium (19.12%), respectively, toward P, N, and K nutrient uptake by hybrid castor. The nutrient contribution from farmyard manure (Co) toward the total uptake was 21.40% of N, 10.35% of P2O5, and 26.06% of K2O, respectively. FPEs for hybrid castor and a ready reckoner of fertilizer dosages were developed using basic data for operational range of soil test values for intended yield target under inorganic fertilization alone and Integrated plant Nutrient System (IPNS) (NPK and FYM). [ABSTRACT FROM AUTHOR]

Soil test crop response (STCR) correlation studies under Integrated Plant Nutrition System were conducted in the western agroclimatic zone of Tamil Nadu during 2020-2021 to devise the fertilizer prescription equations for tomato (Solanum lycopersicum L.) under drip fertigation on an alfisol. The equations were derived by following Ramamoorthy's Inductive cum targeted yield model. The nutrient requirement of N, P2O5 and K2O for producing one quintal of tomato fruit was found to be 0.22, 0.11, 0.27 kg respectively. The per cent contribution of nutrients were 37.93, 46.73 and 29.53 of N, P2O5 and K2O from soil (Cs) and 47.84, 31.12 and 74.13 of N, P2O5 and K2O from fertilizers (Cf) respectively. Two organic sources were applied viz., FYM (Farm Yard Manure) and Biocompost and the per cent contribution of nutrients from FYM were 38.36, 13.22 and 52.17 of N, P2O5 and K2O and from biocompost were 43.34, 10.90 and 57.00 of N, P2O5 and K2O respectively. Fertilizer adjustment equations were formulated for STCR-NPK alone, STCR-IPNS (FYM) and STCR-IPNS (Biocompost) by applying the basic parameters such as NR, Cs, Cf, Cfym, Cbiocompost. A ready reckoner of fertilizer doses for a set of soil test values at yield targets 80 and 90 t ha-1 was computed. The findings also showed that the adoption of STCR-IPNS could save more fertilizers. [ABSTRACT FROM AUTHOR]

A field experiment was conducted on a Typic Ustropept (Irugur soil series) soil of Western Zone of Tamil Nadu to refine the existing fertilizer prescription equation for rainfed maize adopting the inductive-cum-targeted yield model, and fertilizer requirements were quantified for rainfed maize based on soil test and yield target. The basic parameters viz., nutrient requirement (NR) and contributions of nutrients from soil (Cs), fertilizer (Cf) and farm yard manure (Cfym) were computed from the field experimental data. Using the basic parameters, fertilizer prescription equations were developed based on integrated plant nutrition system (IPNS), and nomograms were formulated for the desired yield target of rainfed maize for the given soil test values. The extent of saving of inorganic fertilizers for rainfed maize was computed using the fertilizer prescription equations under IPNS with the application of FYM @ 12.5 t/ha (32% moisture and 0.50, 0.21 and 0.49% of N, P and K, respectively, was 22, 17 and 20 kg of fertilizer N, P2O5 and K2O, respectively, when applied along with the N, P and K fertilizers as per soil test and desired yield target. To validate the fertilizer prescription equations developed for rainfed maize under IPNS, field experiments were carried out during 2013-15 in three locations. The per cent achievement of the targeted yield of all the three verification trials was within ±10% variation proving the validity of the equations for prescribing integrated fertilizer doses for rainfed maize. [ABSTRACT FROM AUTHOR]

Field experiments were conducted on a Typic Rhodustalf (Palaviduthi soil series) soil of Southern Zone of Tamil Nadu by adopting the inductive-cum-targeted yield model, and fertilizer requirements were quantified for glory lily based on soil test and yield target. The basic parameters viz., nutrient requirement (NR) and contribution of nutrients from soil (Cs), fertilizer (Cf) and farm yard manure (Cfym) were computed from the field experimental data. Using the basic parameters, fertilizer prescription equations were developed based on integrated plant nutrition system (IPNS), and nomograms were formulated for desired yield target of glory lily for a range of soil test values. The extent of saving of inorganic fertilizers for glory lily was computed using the fertilizer prescription equations under IPNS. The estimates showed that for the application of FYM @ 12.5 t/ha with 25% moisture and 0.528, 0.261 and 0.501% of N, P and K, respectively, when applied along with the N, P and K fertilizers as per soil test and desired yield target, the saving was 35, 22 and 30 kg of fertilizer N, P2O5 and K2O, respectively. [ABSTRACT FROM AUTHOR]

Soil Test Crop Response correlation studies were carried out in maize under Integrated Plant Nutrition System (STCR-IPNS) on Typic Rhodustalf of Tamil Nadu, adopting "Inductive cum Targeted yield model". The basic parameters for the "Targeted yield model" viz. nutrient requirement (NR), contribution of nutrients from soil (Cs), fertilizer (Cf) and farmyard manure (Cfym) were computed from field experimental data. Using these parameters, the fertiliser prescription equations were developed under IPNS and ready reckoner of fertiliser doses were formulated for desired yield target of maize for a range of soil test values. The quantity of fertilizer nutrients that could be saved due to the application of FYM @ 12.5 t ha-1 was assessed to the tune of 40, 20 and 26 kg fertilizer N, P2O5 and K2O respectively, when applied along with the NPK fertilizers. The per cent reduction in fertilizer N, P2O5 and K2O under IPNS increased with increasing soil available NPK. [ABSTRACT FROM AUTHOR]

Field experiments were conducted in Southern and Western Zones of Tamil Nadu to evaluate the Soil Test Crop Response based fertilizer prescription model under Integrated Plant Nutrition System (STCR-IPNS) for desired yield targets of radish on red calcareous soils (Palathurai series-Typic Rhodustalf). The treatments include control, blanket recommendation, soil test crop response (STCR) based fertilizer dose for an yield target of 40 t ha-1 and 50 t ha-1, STCR-IPNS based fertilizer dose for an yield target of 40 t ha-1 and 50 t ha-1 and farmer's practice. The results of the experiments indicated that, in all the six trials, the per cent achievement of the targeted yield was within ± 10 per cent variation proving the validity of the equations for prescribing integrated fertilizer doses for radish. The highest mean per cent achievement was recorded with STCR - IPNS - 50 t ha-1 (101.3) followed by STCR-NPK alone 50 t ha-1. The highest mean yield was recorded in STCR-IPNS - 50 t ha-1 (50.6 t ha-1) recording an increase of 56.7 per cent over blanket recommendation and 69.0 per cent over farmer's practice. Among the treatments, STCR-IPNS-50 t ha-1 recorded relatively higher RR (81.3 kg kg-1) and BCR (2.24) than other treatments. Post-harvest soil available NPK indicated the build up and maintenance of soil fertility due to soil test based fertilizer recommendation under IPNS. [ABSTRACT FROM AUTHOR]

Field experiments were conducted on a Typic Haplustalf soil of Tamil Nadu by adopting the inductive cum targeted yield model, and fertilizer requirements were quantified for beetroot based on soil test and yield target. The basic parameters [nutrient requirement (NR) and contributions of nutrients from soil (Cs), fertilizer (Cf), and vermicompost (Cvermi)] were computed from the field experimental data. Using these basic parameters, we developed fertilizer prescription equations under the integrated plant nutrition system (IPNS), and nomograms were formulated for the desired yield target of beetroot for a range of soil test values. The quantity of fertilizers that could be contributed by vermicompost at 5 t ha-1 was evaluated as 40, 21, and 30 kg nitrogen (N), phosphorus pentoxide (P2O5), and potassium oxide (K2O), respectively, when applied along with the NPK fertilizers as per soil test and desired yield target. [ABSTRACT FROM AUTHOR]