Development of pelleted organo-mineral fertilizer and its effect on baby corn (Zee mays L.)

Abstract

The present study entitled “Development of pelleted organo-mineral fertilizer and its effect on baby corn (Zea mays L.) was undertaken at Department of Agronomy, College of Agriculture, Vellayani during 2020-2022. The main objectives of the study were standardization of nutrient sources for production of pelleted organo-mineral fertilizers (POMF) and evaluation of its effect on growth and yield of baby corn. The study comprised of two experiments. The Experiment I (a), was conducted at College of Agriculture, Vellayani during November 2021 to January 2022. Organo-mineral fertilizers (OMF) were prepared by mixing organic manures, chemical fertilizers, secondary and micronutrient mixtures, and bio-stimulants in varying ratios on percentage weight basis. The experiment was laid out in completely randomized design with nine treatments and three replications. After thorough mixing of the components, OMF mixtures were pelletized to form POMF using a pelleting machine. The test crop selected for the study was baby corn with a nutrient recommendation of 135:65:45 kg NPK ha-1 (NPK ratio 3:1.4:1). The best six POMF combinations (POMF 1, POMF 2, POMF 4, POMF 5, POMF 6 and POMF 7) satisfying the nutrient ratios of baby corn were selected for further incubation studies. The Experiment I (b), was conducted at College of Agriculture, Vellayani during January 2022 to March 2022. Incubation pot studies were carried out to assess the nutrient release pattern of selected POMF. The experiment was laid out in completely randomized design with six treatments replicated thrice. Among the different combinations of POMF studied, POMF 2 was found to release nutrients in concurrence with the growth stages of baby corn and hence was screened for further field studies. The Experiment I (c) was conducted at College of Agriculture, Vellayani during March 2022 to August 2022. The physico-chemical properties and shelf life of POMF 2 selected from incubation studies were characterized. The nutrient content of POMF 2 (8.18 % N, 3.78 % P and 2.69 % K) remained stable for 4 months and the pellets retained its shape and no fungal growths were observed during the storage period. The Experiment II was conducted at farmers field located at Kakkamoola, Thiruvananthapuram during March 2022 to May 2022 to determine the effect of POMF 2 on growth and yield of baby corn. The variety used was G-5414. The treatments were T1: 100 per cent RD as POMF 2 (basal); T2: 75 per cent RD as POMF 2 (basal); T3: 50 per cent RD as POMF 2 (basal); T4: 50 per cent RD as POMF 2 (basal) + 50 per cent RD as POMF 2 at 25 DAS ; T5: 50 per cent RD as POMF 2 (basal) + 25 per cent RD as POMF 2 at 25 DAS; T6: 25 per cent RD as POMF 2 (basal) + 25 per cent RD as POMF 2 at 25 DAS; T7: FYM @ 12.5 t ha-1+135:65:45 kg NPK ha-1 ½ N+ full P+½ K basal; ½ N +½ K at 25 DAS) ; T8: Control (No fertilizers). POMF 2 was applied on nitrogen equivalent basis for supplying the recommended dose of 135:65:45 kg NPK ha-1 for baby corn. The results revealed that POMF 2 had significant influence on growth, yield and nutrient uptake of baby corn. At 15 DAE, the mineral fertilizer treatment, T7 recorded significantly higher plant height, while at 30 DAE, basal application of even 50 per cent RD as POMF 2 (T2) resulted in plant height comparable to T7. At 45 DAE, application of 100 or 75 per cent RD as POMF 2 recorded the highest plant height and was comparable with the mineral fertilizer treatment (T7). Basal application of 100 or 75 per cent RD as POMF 2 recorded leaf area index comparable with T7 during 15, 30 and 45 DAE. The same trend was observed in dry matter production, cob length and girth also. The basal application of 75 per cent RD as POMF 2 (T2) resulted in cob yields (5.39 t ha-1) comparable to 100 per cent RD as mineral fertiliser, T7 (5.31 t ha-1). The same trend was observed in green stover yield and marketable cob yield also. The basal application of 75 per cent RD as POMF 2 (T2) resulted in NPK uptake comparable with full dose of mineral fertiliser (T7). The soil organic carbon content, soil reaction (pH), electrical conductivity (EC), water holding capacity (WHC) and bulk density of the soil were not significantly influenced by the POMF treatments. The soil organic carbon and pH were found to increase in POMF applied plots compared to mineral fertilizer applied plots. When compared to plots that received mineral fertiliser, POMF treated plots had the highest soil NPK availability. The agronomic efficiency (AE) of N, P and K were found to be higher in organo mineral fertilizer treatments. Basal application of 75 per cent RD as POMF 2 (T2), recorded the highest physiological efficiency (PE) of NPK and was comparable with the mineral fertilizer treatment (T7). Application of 100 or 75 per cent RD as POMF 2 (basal) recorded comparable apparent recovery efficiency (ARE). However, the mineral fertilizer treatment, T7 recorded the least ARE for all the three major nutrients. Application of 25 per cent RD as POMF 2 (basal) + 25 per cent RD as POMF 2 at 25 DAS (T6) recorded the highest partial factor productivity (PFP) and was comparable with T2. The POMF treated plots recorded the highest apparent gain and actual gain in soil available NPK compared to mineral fertilizer treated plots. The treatment T2, recorded the highest gross income (₹ 215991 ha-1) and was on par with T1 (₹ 213784 ha-1) and T7 (₹ 212486 ha-1). Basal application of 75 per cent RD as POMF 2 (T2) recorded the highest net income (₹ 142691 ha-1) and was comparable with 100 per cent RD as mineral fertilizers (T7) (₹ 143783 ha-1). Among the POMF treatments, basal application of 75 per cent RD as POMF 2 (T2) recorded the highest BC ratio (2.95) was on par with the mineral fertilizer treatment, T7 (3.09). Thus from the study, it could be concluded that good quality POMF suited for baby corn can be prepared by mixing cow dung powder (30%), neem cake (10%), groundnut cake (4%), rice husk ash (4%), urea (16%), rock phosphate (9%), single super phosphate (8%), muriate of potash (4%), ayar (1%), rock dust (4%), humic acid (5%) and seaweed powder (5%) on percentage weight basis followed by pelletization. Basal application of cow dung based POMF @ 1.25 t ha-1 (equivalent to 75% RD of NPK of baby corn ie. 102:49:34 kg NPK ha-1) could be recommended as the most productive, profitable, and nutrient use efficient nutrient schedule for baby corn. Thus, twenty-five percentage reduction in recommended dose of NPK for baby corn can be achieved by using POMF rather than seperate application of organic manures and chemical fertilizers. Hence, POMF can be popularized as a promising technology for enhancing nutrient use efficiency in baby corn.