Manure treatment of livestock and poultry to reduce nutrient loss technology

1. Low protein diet formulation technology. With reference to the Compound Feed for Piglets and Growing and Finishing Pigs (GB/T 5915-2020) and the compound Feed for laying and broiler Chickens (GB/T 5916-2020), amino acids and enzymes should be reasonably added to reduce the crude protein content in the diet without affecting the production performance and product quality of pigs and poultry. Improve feed nitrogen utilization efficiency.

2. Optimize manure removal technology for livestock houses. For livestock and poultry farmers using dry manure removal technology, if the frequency of manure removal in the original house is low, the frequency of manure removal can be appropriately increased 1-2 times/day to reduce the residence time of feces in the house; Livestock and poultry farms using the blister manure technology should choose deep pit storage or shallow pit storage technology, and configure trench fans if necessary, and the total daily feces produced by each finishing pig should not exceed 0.015 cubic meters.

3. Biological fermentation bed culture technology. Rice husk, sawdust and crushed straw were used as bio-fermented mattress materials, and microbial agents were sprayed on bedding materials regularly. In situ and under the net biological fermentation bed can be used for poultry breeding, the proportion of rice husks in the bedding is not more than 30%, the thickness of the bedding is not less than 40cm, and the fermentation bed should be turned regularly, at least once a week, to ensure that the bedding and manure are fully mixed. In northern regions with large evaporation, sheep breeding can use in-situ biological fermentation beds, the thickness of bedding is not less than 15 cm, no need to turn over the rake, and the clearance interval is not more than 40 days in non-winter, and not more than 60 days in winter.

4. Enclosure discharge air purification technology. For closed livestock houses with mechanical ventilation, wet purification facilities such as spray device and wet curtain are installed outside the exhaust fan to filter by spraying weakly acidic liquid or liquid containing oxidizing agent such as sodium hypochlorite. The pH value of acidic washing liquid is controlled below 6. Or the air discharged from the livestock house is filtered through the biomass filler, which is mainly made of wood chips, straw and so on. The existing research shows that the use of air purification technology can reduce the intensity of air odor emission by more than 50%.

5. Liquid manure cover storage technology. Including fixed cover storage and floating cover storage. Fixed cover refers to the capping or laminating of liquid waste storage facilities, which should be equipped with gas vents or gas recovery treatment devices to prevent the accumulation of flammable gases. Floating mulching refers to the use of geometric plastic mulching sheets, vermiculite and other floating materials, which is suitable for liquid manure storage facilities with large surface area in areas with less precipitation.

6. Acidified storage technology of liquid manure. By adding acidifiers to reduce the pH value of liquid manure, nitrogen is retained in the form of stable ammonium salt. The commonly used acidifiers are sulfuric acid, superphosphate, etc., adjust the pH to 5.5-6.5, and the acidified liquid manure needs to continue to be stored and fermented. Existing studies have shown that nitrogen loss can be reduced by more than 50% when fecal pH is less than 6.

7. Solid manure airtight compost technology. According to the water content of solid manure, add wood chips, crushed straw and other materials appropriately to ensure piles. Select a suitable place for closed anaerobic fermentation, and the compost period should not be less than 60 days. Wet compost should be selected as a sunny, relatively flat open space with high terrain. Impermeable treatment should be carried out at the bottom, sealed or covered with plastic film around, and rainproof treatment should be done.

8. Solid manure closed composting technology. Including reactor composting and membrane composting. The fermentation time of compost in the reactor is not less than 7 days, and the odor produced in the fermentation process is uniformly purified. Membrane composting should harden the site, cover the expanded polytetrafluoroethylene film above the pile, trap the odor in the pile, regularly ventilate the bottom, and fermentation time is not less than 14 days.

9. Compost bio-based deodorization technology. In the closed workshop of strip and trough aerobic composting, air is sent to the bottom of the biobased filter bed by exhaust fan, and the air is purified through the process of water film absorption and microbial action. Bio-based filter bed is generally made of compost products and wood chips and other biomass materials, water content 50%-65%, while purifying the air to achieve nitrogen recovery. Existing studies have shown that this technology can reduce odor emission intensity by more than 90%.

10. Liquid manure mulch application technology. After applying liquid manure to the soil surface by spraying, pouring, flushing, sprinkling, strip application, drip irrigation, etc., it should be ploughed into the soil in time to reduce the residence time of the manure on the soil surface and reduce the contact area with the air. Liquid manure can also be applied 3-35 cm below the surface of the soil by means of injection fertilization.