Corn straw biogas production

　　In view of the fact that this year's agricultural disaster has been severe, in some areas the corn has basically no cobs, or the corns are small and cannot mature at all, which has seriously affected this year's harvest. In this case, farmers can immediately use these straws to make silage and develop the breeding of beef cattle, dairy cows, sheep and geese to make up for the poor agricultural harvest. Corn straw silage adopts the following methods and steps: (1) Timely harvesting of corn in Northeast China is generally best done in mid-to-late September. At this time, the corn stalks are green and the silage effect is better. (2) Crush or mash the green corn straw. Depending on the objects being raised, use a haymaker or kneader to chop or mash the green corn straw. The length of silage for cattle and sheep should be 3-5 centimeters, and the corn straw for geese should be kneaded into grass powder. During silage, whether to add additional water depends on the moisture content of green corn straw. The moisture content of silage is required to be around 65%-70%. Therefore, if the moisture content of corn straw is low during silage, an appropriate amount of water needs to be added to the crushed raw materials. Generally, corn stalks are crushed (kneaded) and held slightly firmly in the hand. If water droplets can be seen between the fingers, but no dripping, the moisture content is moderate. (3) Installing the cellar: The front four walls of the cellar and the bottom of the cellar should be lined with plastic sheeting (preferably plastic greenhouse film). The joints should be sealed well, and a sufficient length of sealing plastic sheet should be left at the cellar entrance. Then, the straw is processed differently according to the different animals. Generally, the straw fed to cattle and sheep can be chopped into 3-5 cm long. ； For raising geese, a kneading machine is used to knead the straw into grass powder. As the crushed or crushed corn stalks are put into the cellar, they must be compacted (or stepped on) in time. If there is insufficient water, water must be added while loading the cellar. In order to improve the nutritional value, 0.3% (nitrogen content is 46%) urea and a small amount of salt (not more than 0.3%) are added to silage for cattle and sheep, and sprinkled evenly into the raw materials (silage for goose does not add urea). When loading the cellar, the sides, spreads, and sides must be stepped firmly, especially the four sides and corners of the cellar (the most critical technology for the success or failure of silage is anaerobic and moisture content). The number of corn stalks harvested every day depends on the workload of the mowing machine (kneading machine). In principle, the corn stalks should be crushed and put into the cellar on the same day of harvesting. They should not be accumulated overnight to prevent the reproduction of miscellaneous bacteria and mold. When crushing and stacking, keep it clean and do not mix soil and other sharp objects, such as broken glass, nails and wires. Straw must be weighed truck by truck to determine the amount of urea and salt added and to facilitate economic calculations. (4) When capping the silage pit, it must be full. After it exceeds 30-60 cm, cover the top of the pit tightly with plastic film and press it with 50-100 cm of soil. In winter, cover with insulation firewood, etc. according to temperature conditions. The time from loading and storage to capping is required to be short and fast, usually within 3 days, without any interruption in the process. After the roof is capped, the subsidence of the cellar roof should be checked frequently. If gaps and subsidence are found, soil should be added in time to prevent air and rainwater from leaking in.