Model Comparisons for Assessment of NPK Requirement of Upland Rice for Maximum Yield

Upland rice farmers in Malaysia still depend on resultant ash from burning for K and N sources. Efficient use of chemical fertilizers in upland rice needs accurate assessment of required nutrient elements. The present study was performed to determine the N, P, and K requirements of three upland rice varieties grown on idle land (Bukit Tuku soil, AQUIC KANDIUDULT) using four response models. A glasshouse experiment was conducted using 0-200 kg N ha-1 (urea, 46%N), 0-120 kg P2O5 ha-1 (TSP, 45% P2O5), and 0-150 kg K2O ha-1 (MOP, 60% K2O), each at five levels. Three upland rice varieties used in the experiment were Ageh, Kendinga and Strao. The grain yield (14% moisture content) was measured at harvest and fitted using linear (L), linear with plateau (LP), quadratic (Q), and quadratic with plateau (QP) response models. The QP proved itself as the best fitted response model for the determination of fertilizer recommendation rates for maximum yield of upland rice cultivars used. The fertilizer rates were 112 kg N ha-1, 78 kg P2O5 ha-1 and 158 kg K2O ha-1 for Ageh (QP); 138 kg N ha-1 (LP), 87 kg P2O5 ha-1 (QR), 119 kg K2O ha-1 (QP) for Kendinga; and 125 kg N ha-1 (Q), 85 kg P2O5 ha-1 (LP) and 127 kg K2O ha-1 (L) for Strao

Development of Water Soluble NPK Fertilizer for Watermelon Cultivation Under Rain Shelter Structure

Commercial watermelon cultivation at open field depends on granular fertilizer for higher yield and quality. However, application of granular fertilizer is laborious, inefficient, inadequate nutrient uptake and can cause toxicity. Therefore, smart fertigation system as incorporated by IoT (Internet of things) appears to be the best option to improve such issues. To complete the smart fertigation system, application of water-soluble NPK fertilizer is the key tool. Therefore, an experiment was conducted to evaluate and select the optimum water soluble NPK rates used on growth, yield and fruit quality of watermelon under rain shelter structure. Watermelon seedlings were subjected to four water-soluble NPK fertilizer rates at 75%, 100% (Control - 108 kg N, 247.32 kg P and 153.6 kg K ), 125% and 150% based on common practices of NPK granular fertilizer used in watermelon at open field planting system for 65 days. Fertilizer rates induced at 150% significantly increased leaf number, leaf SPAD, total leaf area and leaf dry weight as compared to control at 14.17%, 16.22%, 21.55% and 15.06% respectively. Whereas, application of fertilizer at 125% significantly increased the leaf number, total leaf area and leaf dry weight with the respective increments of 11.5%, 17.19% and 13.08%. Based on regression trendline, application of 125% optimized the performances of the plants such as leaf number, total leaf area and fruit weight. To conclude, increasing 25% NPK standard fertilizer rate (125%) could be promising for watermelon cultivation throughout fertigation under open field planting system. Further trials in open field planting system needs to be undertaken to ensure the selected rates identified from this study could improve the whole performances of watermelo

Increasing the Yield of Upland Rice in Idle Land Through Nutrient and Weed Management

Recently,demand for high quality and fragrant rice has increased markedly due to affluent and health conscious consumers in Malaysia.Research on upland rice had been neglected because of low yield,despite the many good characteristics of upland rice,such as fragrance and long grains size.Furthermore,it has the advantage of cultivation on dry land without accumulation of water.Therefore,a large track of idle land in Malaysia can be developed for upland rice cultivation.This study involves the documentation of upland rice that produce high grain yield and the soil physico-chemical characteristics of idle land.A glasshouse experiment was conducted using Bukit Tuku soil (Aquic Kandiudult) and three selected upland rice varieties (Ageh, Kendinga and Strao) for determination of the optimum levels of N, P, and K fertilizer based on biomass and nutrient partitioning from the earlier survey. The experiment was carried out independently using five levels each of N, P and K with three replicates and arranged in a complete randomized design (CRD).A field trial was conducted on an idle land located in Kampung Kubang Bemban, Kuala Nerang,Kedah to evaluate the weed management practices for selected rice varieties and levels of nutrients obtained in the glasshouse study.In the field survey,35 different upland rice seeds were collected from 17 upland rice fields in Malaysia.The plant and panicle numbers and yields of upland rice varieties ranges from 10 to 18 plants hill-1, 7 to 14 panicles hill-1 and 21 to 50 g yields hill-1, respectively.Both upland rice and forest (as a control) soils were acidic,low in N content and CEC at 0-20 and 20-40 cm depths.Higher Fe content was observed in the soils; a major limitation for upland rice growth.The nutrient contents of idle land were low and higher in Al content.In the glasshouse trial, the yields of upland rice varieties ranged from 7 to 22 g hill-1 (Ageh),6 to 18 g hill-1 (Kendinga) and 9 to 22 g hill-1(Strao) depending on fertilizer types and levels.The optimum fertilizer rate for each variety was determined using different response models. Quadratic (QR) and linear (LR) response models tend to overestimate the fertilizer rates compared to LR and QR with plateau (P) response models. The fertilizer rates were 112 kg N ha-1, 78 kg P2O5 ha-1 and 158 kg K2O ha-1 for Ageh (QRP); 138 kg N ha-1 (LRP),87 kg P2O5 ha-1 (QR),119 kg K2O ha-1 (QRP) for Kendinga; and 125 kg N ha-1(QR), 85 kg P2O5 ha-1 (LRP) and 127 kg K2O ha-1 (LR) for Strao.In the field,there was heavy weed infestation in the unweeded (control) plot.Dazomet was the most effective for controlling weeds for up to 5 months after planting.Due to severe water deficit during this experiment,only estimated yield of Strao rice variety were recorded.Dazomet application at 15 x 15 cm planting distance showed higher yields (7.7 tonnes ha-1) compared to 30 x 30 cm planting distance(2.5 tonnes ha-1).Based on this study, the upland rice can be grown successfully on low land areas,such as on idle land in Peninsular Malaysi