Estimating the Plant Nutrient Uptake of Selected Maize Varieties in Sri Lanka's Dry Zone at Various Fertilizer Rates

Maize is a coarse cereal mostly grown in Sri Lanka's dry zone. Since intense agriculture quickly reduces the soil's fertility, it is crucial to implement appropriate fertilizer management techniques in order to sustain greater output levels. There has been no current research conducted to measure maize's nutrient absorption. Thus, at the Field Crops Research and Development Institute Mahailluppallama in the North Central Province of Sri Lanka (08.600N, 80.270E, 137masl) during Yala, 2022 an experiment was carried out to estimate the nitrogen (N), phosphorous (P), and potassium (K) uptakes of selected maize varieties at the flowering stage under various nutrient management options. Three replicates of a two-factor-factorial experiment in a Randomized Complete Block Design were employed. The fertilizer level (F1 - Zero fertilizer, F2 - Present Department of Agriculture (DOA) inorganic fertilizer recommendation, F3 - 1.5 times of present DOA inorganic recommendation, and F4 - DOA organic fertilizer recommendation) and variety (V1-Pacific 339, V2- MIMZHY 4, V3- Badra) were the two factors tested. The findings showed that whereas P and K uptakes were significantly (P<0.05) greater in Pacific 399 and Badra, respectively, there was no significant difference in N uptake between the maize types at the flowering stage. When no fertilizer was applied, total N was considerably (P<0.05) lower than in F2 and F3, but comparable to F4. Regarding varying fertilizer levels, no discernible significant variation in the overall uptake of P and K was found. All types had comparable total dry weights at 50% blooming; however, under F2 and F3, it was higher than under F1. As a result, whereas N uptake varied according to the various fertilizer application levels, P and K uptake varied amongst types. Overall, it can be said that varying fertilizer levels did not affect the variations' P and K uptake. Variations in fertilizer application levels did not affect N uptake, but varieties did. Thus, while the soil's natural fertility state can supply P and K, proper administration of N fertilizer is necessary for improved growth.