Nutrient omission plot technique for yield response, indigenous nutrient supply and nutrient use efficiency estimation of rice (Oryza sativa L.) crop in Andaman & Nicobar Islands

A nutrient omission plot technique (NOPT) study in RCBD with 8 treatments (omission (-) of N, P, K, NP, NK, PK and no nutrient omission)and 3 replicates per treatment was made on rice at Port Blair, Andaman and Nicobar Islands during kharif 2015 to ascertain yield response and find out the most crucial nutrient for fertilization.The results revealed that yield response to fertilizers (NPK) was 2.63 t / ha (60.74%). The yield response of P (23.3 %) got multiplied by 2.16 and 2.60 times when combined with N and K applications as compared to their individual effects. Indigenous N, P and K supply capacity of the soil was estimated as 70.6, 10.0 and 80.0 kg/ha. Agronomic efficiency (kg grain / kg nutrient applied) was severely limited by P omission (10.13). The economics(Rs/ha) of rice cultivation indicates that omission of NPK & NP fertilizers results in losses. The highest profits realized with no omission (+NPK) were reduced by 52.3% with P omission. Omission of K followed by N and NK has less impact on profits. Rice crop duration got prolonged and shortened under P and N omission while K omission has no such effect.

A Sustainable Way of Fertilizer Recommendation Based on Yield Response and Agronomic Efficiency for Chinese Cabbage

Chemical fertilizer plays an irreplaceable role in raising vegetable output and improving the livelihood of people in China. Chinese cabbage (Brassica chinensis L.) is one of the most common vegetables with a wide planting area. However, there are problems such as the excessive and blind application of chemical fertilizers, which bring about the increase of planting cost and the risk of environmental pollution. So, it is urgent to improve fertilization methods and improve fertilizer use efficiency, aiming to promote the sustainable development of agriculture. In this study, multi-year and multi-site experiments were retrieved from the published literature and public scientific research institutions to study a sustainable fertilizer recommendation method for Chinese cabbage based on yield response and agronomic efficiency. The results showed that the average indigenous nutrients supply of nitrogen (N), phosphorus (P), and potassium (K) were 112.98, 35.03, and 213.15 kg/ha, respectively. It is suggested that these nutrients should not be neglected in the process of fertilizer recommendation. The average yield responses to N, P2O5, and K2O were 26.6, 13.9, and 16.6 t/ha, the relative yields were 0.70, 0.84, and 0.84; also, it was concluded that the agronomic efficiencies were 114.3, 108.5, and 89.4 kg/kg on average, respectively. From these datasets, the theoretical basis of recommended fertilization was established. It was found that there was a significant negative correlation between N, P, and K indigenous nutrient supply and the yield response to N, P2O5, and K2O, and a significant negative linear correlation between yield response and the relative yield of N, P2O5, and K2O. There was also a significant one-dimensional quadratic function relationship between yield response and agronomic efficiency in Chinese cabbage. Then, two years of field experiments for Chinese cabbage were conducted to verify the fertilizer recommendation. It was concluded that fertilizer recommendation for Chinese cabbage based on yield response and agronomic efficiency was a sustainable way for farmland utilization, not only economically and suitably satisfying its application on fields of different sizes, but also taking into account the indigenous nutrient supply and the interaction between N, P, and K, having shown the advantages of high efficiency, especially when the conditions such as soil testing and plant diagnosis were not sufficient.

SITE-SPECIFIC NUTRIENT MANAGEMENT FOR MAIZE HYBRIDS IN AN INCEPTISOL OF WEST BENGAL, INDIA

SUMMARYThe area under hybrid maize cultivation is increasing rapidly across South Asia. However, information regarding the proper nutrient management for modern stay-green maize hybrids in India is not adequate resulting in low productivity. Existing nutrient management practices are not able to capture the momentum change in the scenario of soil nutrient supply capacity and plant nutrient demand for achieving higher yield target. The present study aims at establishing the site-specific nutrient management (SSNM) package for an inceptisol (West Bengal, India). Soil indigenous nutrient supply capacity and nutrient use efficiency was also evaluated by using the nutrient omission plot technique. The experiment was laid out in strip-plot design, assigning three maize hybrids (P 3522, P 3396 and Rajkumar) in the vertical strip and nine fertilizer treatments [50% RDF/Recommended dose of fertilizer, 75% RDF, 100% RDF (200-60-60 kg N-P2O5-K2O ha−1), 125% RDF, 150% RDF, 100% PK, 100% NK, 100% NP and control (zero-NPK)] in the horizontal strip, with three replications. Results of the experiment revealed that the differences among cultivars were generally non-significant. The maize hybrids showed greater yield response to fertilization with N (4.14 Mg ha−1) during winter, followed by K (2.54 Mg ha−1) and P (1.58 Mg ha−1). Indigenous nutrient supply was estimated 107.2, 37.6 and 107.7 kg ha−1 for N, P and K, respectively. Both average agronomic efficiency (AE) and recovery efficiency (RE) were increased with 50% RDF and it decreased with further increase in NPK levels up to 150% RDF. The average internal efficiency (IE) was higher with 50% RDF closely followed by the treatment with absence of N. As grain yields and gross return over fertilizer (GRF) under 75 to 150% NPK treatments were similar, nutrient doses of 150 kg N, 45 kg P2O5 and 45 kg K2O ha−1 were recommended as optimum for maize hybrids.

Effects of NPKS on Yield and Nutrition of BRRI dhan49

Nitrogen (N), phosphorus (P), potassium (K) and sulphur (S) strongly influence rice plant nutrition. Present experiment was conducted at the Bangladesh Rice Research Institute (BRRI) farm, Gazipur in a permanent layout in wet season of 2014. Objectives of the research were to study the effects of NPKS on grain yield, plant nutrition, requirement of NPKS to produce one ton grain and to estimate the indigenous nutrient supply of the soil. BRRI dhan49 was tested with NPKS (complete), PKS (-N), NKS (-P), NPS (-K) and NPK (-S) fertilizer packages. The NPKS were applied @ 100-7-80-3 kg ha-1. Omission of each nutrient from the complete treatments significantly reduced grain and straw yields of BRRI dhan49. The highest yield reduction was recorded because of N omission followed by K. Nutrient concentration in grain and straw as well as nutrient uptakes were significantly affected by major plant nutrients. Nutrient uptake was directly related to the biomass production. About 87% of total K uptake remained in straw and thus a good K source for rice cultivation. Nitrogen, P, K, S and Zn required to produce one ton rice were 20.88, 5.04, 18.77, 2.08 and 0.07 kg, respectively. The indigenous N, P, K and S supply capacity of this soil was 37, 13, 41 and 6 kg ha-1, respectively.Bangladesh Rice j. 2016, 20(2): 39-47

Assessment of Indigenous N, P and K Supply for Rice Site Specific Nutrient Management in Buru Regency

Rate of fertilizer that should be applied to rice soil based on Site Specific Nutrient Management (SSNM) depends on indigenous nutrient supply, its recovery efficiency, and the amount of nutrients requirement to achieve the yield target. Research on nutrient omission plot was conducted in farmers irrigated land on Waeapo plain, Buru Island. In this area, N, P, and K were the main limiting factors of rice growth and yield. To overcome the constraint, this assessment was conducted to determine the indigenous supply of N, P and K and optimal target of rice productivity. Results of this assessment showed that the average of rice optimum productivity (Mg grain water content/w.c. 14% ha-1) in Waeapo plain was 6.55 Mg DGM (Dry Grain Milled) ha-1, with range from 5.6 to 7.3 Mg DGM ha-1 depended on the indigenous supply of N, P and K. The average value of the indigenous N, P and K supplies in Waeapo plain Buru was 65.59 kg N ha-1, 13.70 kg P ha-1 and 78.65 kg K ha-1, respectively while average productivity of rice on that indigenous N, P and K supplies was 5.05, 5.96 and 6.05Mg DGM ha-1, respectively. The value of indigenous nutrient supply of this nutrient can be used as a basis of fertilizer recommendation with the SSNM concept. Keywords: Indigenous nutrient supply; nitrogen; phosphorus; potassium; Site Specific Nutrient Management [How to Cite: Andriko NS and MP Sirappa. 2014. Assessment of Indigenous N, P and K Supply for Rice Site Specific Nutrient Management in Buru Regency. J Trop Soils 19: 151-159. Doi: 10.5400/jts.2014.19.3.151]