A Complete Analysis of the Key Technical Points for Soil Testing and Formula Fertilization in Spring Corn
1. Choose suitable varieties. Select suitable and superior varieties according to local conditions; based on heat resources and actual production conditions, choose medium-to-late maturing varieties with a growth period of 120-130 days. Among spring corn varieties with relatively outstanding comprehensive traits, the main one is Nongda 108, etc. 2. Fine land preparation. Spring corn requires deep plowing, and the earlier the autumn plowing...
1. Fertilizer requirement characteristics: Corn absorbs the most nitrogen throughout its entire growth period, followed by potassium, and less phosphorus. Regarding nitrogen absorption, before tasseling and fertilization, 85% of the total nitrogen amount has already been absorbed. Regarding phosphorus absorption, 70% has already been absorbed before tasseling. Regarding potassium absorption, more than 70% has already been absorbed before tasseling, and the remaining 30% is absorbed at tasseling and fertilization; therefore, potassium fertilizer generally needs to be applied in the early growth stage. Returning straw directly to the field as base fertilizer for corn has good effects. In soils with relatively low fertility, a small amount of nitrogen fertilizer should be applied together with the straw to adjust the carbon-to-nitrogen ratio and accelerate straw decomposition.2. Fertilization technology: Under medium fertility levels, the fertilizer application rate per mu for the entire growth cycle of spring corn is 1500-2000 kg of farmyard manure (or 250-300 kg of commercial organic fertilizer), 15-17 kg of nitrogen fertilizer, 4-5 kg of phosphorus fertilizer, and 8-9 kg of potassium fertilizer. Nitrogen fertilizer and potassium fertilizer are divided into base fertilizer and two topdressings, while phosphorus fertilizer is all used as base fertilizer, and chemical fertilizers and farmyard manure (or commercial organic fertilizer) are applied mixed. Base fertilizer: apply 1500-2000 kg of farmyard manure or 250-300 kg of commercial organic fertilizer per mu, 5-6 kg of urea, 9-11 kg of diammonium phosphate, and 5 kg of potassium chloride; in zinc-deficient soil, 1-2 kg of zinc sulfate can be applied per mu. It is recommended to apply slow-release fertilizer, and to advocate returning straw to the field to improve soil fertility. Topdressing: Topdressing at the small trumpet stage: apply 14-15 kg of urea and 7-8 kg of potassium chloride per mu. Topdressing at the large trumpet stage: apply 8-9 kg of urea and 4-5 kg of potassium chloride per mu. Foliar topdressing: if zinc was not applied in the base fertilizer, seeds can be soaked with zinc fertilizer using a 0.02-0.05% zinc sulfate solution for 12-24 hours; for seed dressing, use 2-3 g of zinc sulfate per 1 kg of seed, dilute with a small amount of water, and mix evenly with the seeds; for foliar spraying, a 0.05-0.1% zinc sulfate solution can be sprayed at the seedling stage or jointing stage. For boron deficiency, seeds can be soaked with boron fertilizer using a 0.01-0.05% boric acid solution for 12-24 hours.