In view of the problems in radish production such as heavy nitrogen and phosphorus fertilizer and light potassium fertilizer, disproportionate nitrogen, phosphorus and potassium, unreasonable application period of phosphorus and potassium fertilizer, apparently insufficient application of organic fertilizer and insufficient attention to the application of trace elements, the following fertilization principles are proposed.
(1) Optimize the dosage of nitrogen, phosphorus and potassium fertilizers according to soil fertility conditions and target yield, paying special attention to adjusting the dosage of nitrogen and phosphorus fertilizers and applying more potassium fertilizers.
(2) calcareous soil with low content of effective manganese, zinc, boron, molybdenum and other trace elements, attention should be paid to the supplementation of trace elements; vegetable land with serious acidification should be moderate application of lime and other acidic soil conditioners.
(3) Reasonable application of organic fertilizers obviously increases the yield and improves the quality of radish, avoid using organic fertilizers that are not fully decomposed, and advocate the application of commercial organic fertilizers and decomposed farmyard manure.
(1) Organic fertilizer application amount: small radish (such as four-season radish) with yield level of 15,000-22,500 kg/ha can apply organic fertilizer 7.5~15 square/ha; high-yielding varieties with yield level of 67,500-75,000 kg/ha apply organic fertilizer 15~45 square/ha.
(2) Radish yield level above 60,000 kg/ha: Nitrogen fertilizer (N) 225~270 kg/ha, phosphorus fertilizer (P2O5) 75~105 kg/ha, potassium fertilizer (K2O) 180~210 kg/ha.
(3) Radish yield level 62,500~45,000 kg/ha: Nitrogen fertilizer (N) 150~195 kg/ha, phosphorus fertilizer (P2O5) 60~90 kg/ha, potassium fertilizer (K2O) 150~180 kg/ha.
(4) Yield level of radish 15000~22500 kg/ha: Nitrogen fertilizer (N) 90~135 kg/ha, phosphorus fertilizer (P2O5) 45~75 kg/ha, potassium fertilizer (K2O) 120~150 kg/ha.
If the base fertilizer is not applied with organic fertilizer, nitrogen (N) 45~75 kg/ha and potassium (K2O) 30~45 kg/ha can be added as appropriate.
For plots prone to boron trace element deficiency, or fields with boron deficiency symptoms in previous years, apply 15 kg of borax per hectare before sowing radish, or foliar spray with 0.1%~0.5% borax or boric acid aqueous solution in the middle and late stages of radish growth (also can be mixed with pesticide), once every 5~6 days, 2~3 times in a row.
All organic fertilizers are applied as base fertilizers, 40% of the total nitrogen fertilizers are applied as base fertilizers, 60% are applied as follow-up fertilizers twice during the rosette period and the early stage of fleshy root growth of radish.