Table of Contents
Cow manure, as a common organic waste, is rich in organic matter and nutrients, and can become a high-quality organic fertilizer after proper treatment. This paper will introduce in detail the methods of using cow manure as fertilizer, including the characteristics of cow manure, treatment methods, application techniques and precautions, etc., to provide reference for farmers and agricultural practitioners.
Characteristics of cow manure
Cow manure is rich in nutrients
Cow manure contains a large amount of organic matter, nitrogen, phosphorus, potassium and other nutrients, which is a high-quality organic fertilizer. Among them, the content of organic matter is generally between 15% – 25%, nitrogen content is between 0.3% – 0.5%, phosphorus content is between 0.2% – 0.3% and potassium content is between 0.5% – 1.0%. In addition, cow manure is rich in trace elements and beneficial microorganisms, which have a positive effect on soil improvement and crop growth.
Cattle manure is loose in texture
Cow manure has a relatively loose and permeable texture, which is conducive to soil microbial activity and root growth. Compared with other organic fertilizers, cow manure has unique advantages in improving soil structure.
Cow manure is widely available
Cow manure is one of the major waste products of animal husbandry and is available from a wide range of sources and in large quantities. In rural areas, almost every household has cattle, and the collection of cow manure is relatively easy. At the same time, with the development of large-scale farming, large-scale cattle farms also provide convenient conditions for the centralized treatment and utilization of cow manure.
Characteristics of cow manure
Methods of cow manure for fertilizer
natural composting
Selection of composting sites
Choose a place with high terrain, good drainage, ventilation and air permeability as the composting site. The area of the composting site should be determined according to the quantity of cow manure and the composting time, generally each cubic meter of cow manure needs to occupy 1.5 – 2 square meters of composting site.
Composting material preparation
In addition to cow manure, some auxiliary materials such as straw, leaves and hay need to be prepared. These auxiliary materials can provide a carbon source, regulate the carbon to nitrogen ratio of the compost and promote microbial activity. Generally speaking, the ratio of cow manure to auxiliary materials is 3:1.
Composting methods
Cow manure and auxiliary materials are mixed well and then piled up to form a heap of a certain shape. The height of the pile is usually 1.5 – 2 meters, the width is 2 – 3 meters, and the length is unlimited. In the process of stacking, attention should be paid to the compaction of the pile to ensure the aeration and stability of the compost. In the early stage of composting, the temperature of the heap will rise rapidly due to the activity of microorganisms that generate a lot of heat. When the temperature of the pile reaches 50 – 60 ℃, the pile should be turned to ensure the uniformity and aeration of the compost. The frequency of turning is usually once a week. When the temperature of the compost pile drops below 40℃, it indicates that the compost pile has been ripened and can be used as fertilizer.
Methods of cow manure for fertilizer
Biogas digester fermentation
Biogas digester construction
The construction of a biogas digester is an important step in the fermentation process using cow manure. The construction of biogas digester should be determined according to the scale of breeding and gas demand, generally 1 – 2 cubic meters of biogas digester is needed for cow. The construction of biogas digester should comply with relevant technical standards and safety requirements to ensure the sealing and stability of the digester.
Cow manure in biogas digester
Mix cow manure with appropriate amount of water and pour it into the digester. In the process of entering the digester, attention should be paid to controlling the concentration of cow manure and the speed of entering the digester, so as to avoid excessive foam and pressure in the digester. Generally speaking, the concentration of cow manure should be controlled between 8% – 10%, and the rate of entry should be determined according to the volume of the digester and gas production.
Fermentation process management
Cow dung in the digester will ferment under the action of microorganisms to produce biogas and methane. During the fermentation process, care should be taken to control the temperature, humidity and pH in the digester to ensure that the fermentation process runs smoothly. Generally speaking, the temperature in the digester should be controlled between 15 – 35℃, humidity between 60% – 80% and pH between 6.8 – 7.5. At the same time, the biogas digester should be stirred and drained regularly to ensure even distribution of materials in the digester and fermentation effect.
Cow manure for fertilizer
Liquid and residue after digester fermentation are high-quality organic fertilizers, which can be directly used to fertilize farmland. Biogas is rich in nitrogen, phosphorus, potassium and other nutrients and a variety of trace elements, with strong quick-acting and high fertilizer efficiency. The digestate contains a large amount of organic matter and humus, which has the function of improving soil structure and soil fertility. In the application of biogas and digestate, attention should be paid to the control of application amount and application method to avoid soil pollution and crop root burning.
Biogas digester fermentation
High temperature aerobic fermentation
Selection of fermentation equipment
High-temperature aerobic fermentation requires the use of specialized fermentation equipment, such as fermenters and fermentation tanks. These equipments can provide suitable temperature, humidity and oxygen conditions to promote rapid fermentation of cow manure. When selecting fermentation equipment, it should be determined according to the quantity of cow manure and processing requirements to ensure that the performance and quality of the equipment meets the requirements.
Control of fermentation conditions
The key to warm aerobic fermentation is to control the fermentation conditions, including temperature, humidity, oxygen content and fermentation time. Generally speaking, the fermentation temperature should be controlled between 55 – 65℃, humidity should be controlled between 50% – 60%, oxygen content should be maintained between 10% – 15%, and the fermentation time is 7 – 10 days. During the fermentation process, the fermentation conditions should be adjusted through ventilation and stirring to ensure the smooth progress of the fermentation process.
Cow manure as fertilizer
Fermented cow manure product is a high quality organic fertilizer that can be used directly for fertilizing farmland. Before application, it should be properly processed, such as crushing and sieving, in order to improve the uniformity and application effect of the fertilizer. Meanwhile, it can also be processed into granular organic fertilizer through organic fertilizer production line, which can be convenient for fertilizer storage and organic fertilizer sales.
High temperature aerobic fermentation
Using cow manure as fertilizer is an economical, environmentally friendly and efficient way of agricultural production. Through reasonable treatment methods and application techniques, cow manure can be converted into high-quality organic fertilizers, providing rich nutrients for crops and promoting soil improvement and sustainable agricultural development.
