Penentuan Takaran Pupuk Nitrogen pada Tanaman Jagung Hibrida Berdasarkan Klorofil Meter dan Bagan Warna Daun
Determining the Rate of Nitrogen Fertilizer on Hybrids Maize Based on Chlorophyll Meter and Leaf Color Chart. Synchronization the amount of N nutrient needed for maize growth and the availability of indigenous N in the soil + N fertlizer, is important to obtain a high maize yield. An alternative technique to identify the N nutrient adequacy on maize is by using the chlorophyll meter or the leaf color chart (LCC). The research objective was to determine the rate and time of N fertilizer
... fertilizer application for hybrids maize based on the content of N in the leaf as measured by chlorophyll meter and LCC. The experiments were conducted using a split plot design with three replications. The main plots were the rate of N fertilizer, namely 0, 75, 150, and 225 kg N/ha. The subplots were the corn varieties Pioneer 21 and Bisi 2. Results showed that the N fertilizer requirements for maize crops as measured using the chlorophyll meter and the LCC were positively correlated with the actual levels of N requirement. Both measurement techniques can be used to identify the N nutrient requirement for maize during the plant growth stages V12 and VT. Determination of the critical N status by grouping stages of plants with sufficient and insufficient N nutrient indicated that chlorophyll meter value was more accurate than the use of LCC. The deviation of measurements of N fertilizer requirements at plant growth stages V12 and VT using the chlorophyll meter was smaller (11.1% and 2.7%) than those using the LCC (16.1% and 8.3%). The critical N status as measured using the chlorophyll meter and the LCC at V12 was 52 units, and the BWD 4.7, whereas the critical N status at VT was 50 units using the chlorophyll meter and scale 4.4 using the LCC. The estimated N fertilizer required at V12 with maize yield target of 9-10 t/ha was the value of the chlorophyll meter <41unit or the LCC <4 with the rates of N fertilizers of 125-131 kg/ ha. If the chlorophyll meter value was 42-46 units or LCC 4.0 to 4.2, the rates of N fertilizer to be applied ranged from 87-119 kg N/ ha. With the value of the chlorophyll meter 47-50 units or values of LCC 4.3 to 4.5, the rate of N fertilizer required ranged from 46-78 kg N/ha.