DYNAMICS OF NITROGEN AND PHOSPHORUS UNDER MAIZE - BLACKGRAM - GROUNDNUT CROPPING SEQUENCE IN RED LOAMY SOILS
| dc.contributor.advisor | Dr. T. GIRIDHARA KRISHNA | |
| dc.contributor.author | BELLARY USHASRI | |
| dc.date.accessioned | 2024-05-23T13:10:42Z | |
| dc.date.available | 2024-05-23T13:10:42Z | |
| dc.date.issued | 2024-05-23 | |
| dc.description.abstract | A field experiment entitled “Dynamics of nitrogen and phosphorus under maize - blackgram - groundnut cropping sequence in red loamy soils” was conducted (2019-2020) at S.V. Agricultural College, wet land farm, Tirupati. The experimental soil was sandy loam in texture, slightly acidic in reaction, low in organic carbon and available nitrogen, high in available phosphorus, medium in available potassium. All the micro-nutrients (Mn, Zn and Cu) were above the critical limits, except Fe. The experiment was laid out in a randomized block design and replicated thrice. Ten treatments viz., control, fertilizers applied at 50, 75 and 100% of the recommended dose (N240P80K80), N240 only, P80 only, FYM (@ 5 t ha-1) applied alone, and in combination with100%,75% and 50% recommended NPK were applied to maize. These treatments were compared with no-fertilizer and manure control. Blackgram was grown following maize without any fertilizer or manure application. It was allowed to grow till maturity, and after two pickings, the stover was incorporated into the soil. On the same field where blackgram was grown, each main plot treatment of RBD was split into three sub plot treatments with three levels of recommended dose of fertilizers viz., S1 (control), S2 (75% RDF) and S3 (50% RDF) resulting in ninety treatment combinations replicated three times in split plot design and groundnut grown as test crop in kharif. Application of organic manures and inorganic fertilizer showed the influence on physico-chemical properties of soil at harvest in maize, the highest organic carbon (0.56%), available nitrogen (110 kg ha-1) and phosphorus (35.1 kg ha-1) in soil were recorded with application of 100% RDF (T3) and this was on par with 100 % RDF+ FYM @ 5 t ha-1 (T8) and 75 % RDF + FYM @ 5 t ha-1 (T9) in case of organic carbon and phosphorus. Among subplots, S2 is significantly superior over S3 and S1 pertaining to available nitrogen (112 kg ha-1) and phosphorus (24.0 kg ha-1). The highest blackgram haulm yield was obtained in the treatment T3 (6472 kg ha-1) where 100% RDF was added to maize. The higher N, P and K uptake of blackgram at flowering was registered by T9 (212, 71.3 and 214 kg ha-1 , respectively). xviii Among the treatments applied to maize T8 (100 % RDF+ FYM @5 t ha-1) resulted in higher groundnut pod, haulm yield and total dry matter of 2426, 2363 and 4789 kg ha-1 respectively. While S2 (75% of recommended dose for groundnut) recorded the highest pod, haulm yield of 2256 and 2443 kg ha-1 and total dry matter of 4699 kg ha-1 and it was superior to the S3 and Sl . The highest available N, NH4-N and NO3-N content of 131, 17.2 and 38.5 mg kg-1 soil were maintained under the treatment T3, where optimum dose of NPK was applied. The values of total, available, NH4-N and NO3-N further decreased, T3 (100% RDF) recorded the highest as 110, 9.5 and 27.3 mg kg-1 at maize harvest. The treatments T6 (17.8 mg kg-1) and T3 (27.2 mg kg-l) showed substantial increase in the NH4-N and NO3-N content of the soil at 50 % flowering of groundnut and decreased at harvest. Among the organic N fractions viz., hydrolysable organic amino sugar N (ASN), amino acid N (AAN) and ammonia N (NHN) were significantly higher with application of 100 % RDF (T3), however, it was on par with that of application of 100% RDF + FYM @ 5 t ha−1 (T8), 75 % RDF + FYM @ 5 t ha−1 (T9), 75 % RDF (T4) and 100% N (T6) under all the crops throughout the cropping period. The subplot treatment S2 (75% of recommended dose) was superior to S3 and S1 in influencing the Olsen P content of the soil. These treatments also maintained higher values of the inorganic P fractions (LB - P, Al - P, Fe - P, RS- P, Occl - P and Ca - P). Among all, calcium bound P (Ca-P) was the most dominant P fraction in the experimental soil, comprising about 15-33% of the total inorganic P, next dominant fraction was the reductant soluble P (RSP), constituting 14 to 22% of inorganic P. Residual P content of the soil was highly variable, with values ranging from 4.5 to 36.5%. Total-N, available N, NH4-N and NO3-N content of the soil at silking stage of maize positively affected maize yield and N uptake at maturity. Organic N content of soil at maize harvest stage could significantly relate with grain yield and stover yield (r = 0.730*, 0.637*), grain, stover N uptake (r = 0.716*, 0.745*) and total N uptake (r = 0.753*). Particularly AAN, ASN and NHN hydrolysable N fractions positively influenced the maize yield, N uptake of grain and stover during all the stages. Among the hydrolysable N fractions AAN, ASN and NHN exhibited significant correlation with total yield and N uptake, at flowering stage (r values were 0.788** and 0.855**, respectively in case of AAN, 0.880**, 0.926** and 0.728*, 0.812**, respectively in case of ASN and NHN). Hyd.N fractions determined at flowering and harvest stages of groundnut influenced yield and N uptake, with UIN exhibiting negative values of 'r'. Inorganic P content of soil at silking stage of maize correlated significantly with total yield (r = 0.707*) and total P uptake (r = 0.772*). The total yield (r = 0.644*) and P uptake (r = 0.664*) by maize were found to be significantly correlated with LB-P fraction at the harvest. Phosphorus uptake by both grain and haulm was significantly influenced by all fractions except Res-P at flowering stage as well as before incorporation of blackgram. Both yield and P uptake by groundnut were direct functions of total, inorganic and Olsen P at before sowing, 50% flowering and at harvesting of groundnut. LB-P during all the growth stages of groundnut was found to influence both yield and P uptake. xix Ammonical-N (NH4-N), ASN and UIN contents of soil at silking stage of maize could explain the variation in maize yield to the extent of 63.1% and at the harvest stage, NO3-N fraction of soil inorganic N could predict the grain yield to the extent of 56.4 %. While pod yield of groundnut was predicted to an extent of 88.0% with the help of UIN, NH4-N, ASN, NO3-N and NH3 - N fractions of soil N. The soil inorganic fractions of P, viz., Org-P, LB-P, Al-P, RS-P and Occ-P determined before sowing of groundnut were found to explain the variability in pod and total yield at maturity to an extent of 98.8 and 98.1%. | |
| dc.identifier.other | D6585 | |
| dc.identifier.uri | https://krishikosh.egranth.ac.in/handle/1/5810209394 | |
| dc.keywords | DYNAMICS | |
| dc.keywords | NITROGEN AND PHOSPHORUS | |
| dc.keywords | MAIZE - BLACKGRAM - GROUNDNUT | |
| dc.keywords | T CROPPING SEQUENCE | |
| dc.language.iso | English | |
| dc.pages | 291 | |
| dc.publisher | Acharya N G Ranga Agricultural University | |
| dc.relation.ispartofseries | D6585; D6585 | |
| dc.sub | Soil Science and Agriculture Chemistry | |
| dc.theme | DYNAMICS OF NITROGEN AND PHOSPHORUS UNDER MAIZE - BLACKGRAM - GROUNDNUT CROPPING SEQUENCE IN RED LOAMY SOILS | |
| dc.these.type | Ph.D | |
| dc.title | DYNAMICS OF NITROGEN AND PHOSPHORUS UNDER MAIZE - BLACKGRAM - GROUNDNUT CROPPING SEQUENCE IN RED LOAMY SOILS | |
| dc.type | Thesis |