ผลของการจัดการปุ๋ยภายใต้ระบบการให้น้ำที่แตกต่างกันต่อการเติบโต ผลผลิต และคุณภาพของข้าวโพดหวาน

Abstract

The study on the effects of fertilizer management under different watering systems on growth, yield, and quality of sweet corn was divided into 2 parts including (1) the study of the nutrient requirement for sweet corn production and (2) evaluation the fertilizer management effect under different irrigation systems on growth, yield, and quality of sweet corn. Nutrient requirements of sweet corn (Zea mays L. saccharata) were evaluated from December 2016 to March 2017. Three commercial sweet corn varieties, Hi-brix 53, WAN 54, and Sugar star plus were selected for this study. The study was carried out in Mae Hia Agricultural Research, Demonstrative and Training Center, Faculty of Agriculture, Chiang Mai University. The crop was seeded by hand and thinned to ensure a uniform within-row spacing 25 x 75 cm. After planting, the sweet corn samples were collected according to the growth stage. The fresh and dry weight of stover and yield (fresh ear) were recorded. Then the concentration of nutrients in each plant part was analyzed for determining plant nutrient uptake by sweet corn. The results showed that the commercial sweet corn yielded 2.98 t/rai required plant nutrients (per rai) as follows: 27.08 kg N, 4.01 kg P, 25.76 kg K, 4.09 kg Ca, 2.37 kg Mg, 2.24 kg S, 269.65 g Fe, 127.60 g Mn, 85.51 g Zn and 17.53 g Cu. Besides, the nutrient removals of sweet corn (nutrients accumulated in ears) (per rai) were as follows:10.32 kg N, 2.42 kg P, 9.06 kg K, 0.55 kg Ca, 1.12 kg Mg, 1.33 kg S, 39.18 g Fe, 25.14 g Mn, 25.12 g Zn and 6.00 g Cu. The study on the fertilizer management effect under different irrigation methods on growth yield and yield quality of sweet corn was conducted in the research field at Faculty of Agriculture, Chiang Mai University and farmer’s field at Mae Sao sub-district, Mae Ai district during November 2017 to March 2018 and December 2018 to May 2019. The experimental design was a randomized complete block design (RCBD) with 4 replications and 5 treatments as follows: (1) soil fertilization at the rate of 25.9: 7.5: 7.5 N: P2O5: K2O kg/rai (based on nutrient requirement and soil analysis data, or site-specific fertilizer management, SSFM) with furrow irrigation, (2) soil fertilization (SSFM rate) with drip irrigation, (3) fertigation (SSFM rate) by drip irrigation, (4) soil fertilization at the rate of 30.5: 7.5: 7.5 N: P2O5: K2O kg/rai (common rate for sweet corn production) with furrow irrigation, and (5) control treatment (non-fertilization and irrigated by furrow). The results showed that the season and location affected sweet corn growth and yield significantly. Although the fertilization based on SSFM did not affect plant height, leaf greenness value, primary nutrient content in ear-leaf, fresh yield, and yield quality significantly when compared to farmer practice treatment. However, the fertigation based on SSFM and applied at the same time of drip irrigation trended to promote the growth of sweet corn. Besides a good yield and quality of sweet corn and maximum fertilizer use efficiency were observed. In the 2017/2018 growing season, sweet corn, Hi-brix 59 variety was tested. At the research field (sandy loam soil), sweet corn had 4.03 t/rai of the average fresh yield, average fresh ear weight 438.92 g/ear, ear length 37.54 cm, ear diameter 64.92 mm, and the total soluble solids 15.39 ° Brix. With the farmer’s field (loam soil), sweet corn had 3.12 t/rai of the average yield, average fresh ear weight 352.07 g/ear, ear length was 34.60 cm, ear diameter 61.55 mm, and total soluble solids 15.24 ° Brix. Moreover, the drip irrigation system saved 50% water usage in the sandy loam soil and 25% in the loam soil compared to the furrow system. The results of the study indicated that the fertilizer rate based on the nutrient requirements of sweet corn and soil analysis data and applied with drip irrigation is an appropriate fertilizer and water management for sweet corn production.