Key Technical Points for Fertilization in the Production of Pollution-Free Fruit

1. The use of organic fertilizers, commercial organic fertilizers, and microbial fertilizers is encouraged. On the premise that chlorine-containing compound fertilizers and nitrate nitrogen fertilizers are prohibited, chemical fertilizers are permitted to be used according to the following two principles.

(1) Chemical fertilizers must be applied in combination with organic fertilizers, and the amount of inorganic nitrogen applied should not exceed the amount of organic nitrogen used.

(2) Chemical fertilizers may also be applied in combination with organic fertilizers and compound microbial fertilizers, with the formula being 1000 kg of barnyard manure, 5-10 kg of urea or 20 kg of diammonium phosphate, and 60 kg of compound microbial fertilizer; the final topdressing must be carried out 30 days before charging.

2. The use of untreated municipal domestic waste and industrial waste is prohibited. Municipal domestic waste and industrial waste must undergo harmless treatment and meet the requirements of GB8172 before they can be used. The annual application rate per hectare of orchard is limited to no more than 45000 kg on clayey soil and no more than 3000 kg on sandy soil.

3. Farmyard manure should in principle be produced and used locally; external farmyard manure should only be used after it has been confirmed to meet the requirements. Regardless of the raw materials used to make compost, farmyard manure must undergo high-temperature fermentation to kill parasitic eggs, pathogenic bacteria, and weed seeds, so that it meets harmless sanitation standards. For high-temperature compost, the compost temperature is required to reach a maximum of 50-55°C and be maintained for 5-7 days; the mortality rate of Ascaris eggs is 95%-100%; flies are effectively controlled from breeding, and there are no live maggots, pupae, or newly emerged adult flies around the compost pile. For biogas fermentation fertilizer, the sealed storage period is required to be more than 30 days; the high-temperature biogas fermentation temperature is 53±2°C and is maintained for 2 days; the sedimentation rate of parasitic eggs is above 95%, and no live schistosome eggs or hookworm eggs may be picked out from the water and manure liquid; the residue in the biogas digester may only be used after harmless treatment.