Manure
Manure
Horse dung, a type of manure.
Manure is a solid waste product from animals that is widely used as an organic fertilizer in agriculture. It contains high levels of nitrogen, phosphorus, potassium and other nutrients. Manure decomposes over time through bacterial and microbial action and in the process releases these nutrients into the soil. This slow release mechanism is a great benefit to farmers as it limits the leaching of nutrients into the ground water, making it available to plants over a longer period of time. Manure also adds organic matter to the soil, increasing the quality of the soil itself.
Plants can only absorb nutrients that are dissolved in water. When manure decomposes, the nitrogen compounds are converted to a form that is soluble in water, for example nitrates (\(\text{NO}_{3}^{-}\)). The nitrates are dissolved in the moisture in the soil and plants are then able to absorb the nitrogen compounds through their root system.
Advantages of Manure and Compost to the Soil
Manure and compost not only supply many nutrients for crop production, including micronutrients, but they are also valuable sources of organic matter. Increasing soil organic matter improves soil structure or tilth, increases the water-holding capacity of coarse-textured sandy soils, improves drainage in fine-textured clay soils, provides a source of slow release nutrients, reduces wind and water erosion, and promotes growth of earthworms and other beneficial soil organisms. Most vegetable crops return small amounts of crop residue to the soil, so manure, compost, and other organic amendments help maintain soil organic matter levels.
How to Make Organic Fertilizers
As for organic fertilizer production, you can use fast composting. Fast composting is a composting technique used by many biodynamic farmers. A pit of 1m height, 1m width and 1m length is prepared. The length of the pit can be increased according to the space available in your garden and your compost requirement. The pit is filled in with a thin layers of leaves, manure, and straws.
Water is added after adding each layer. You can also add some soil between these layers. The pile should be turned regularly to keep it aerated. Compost turner is the necessary machine in this process. You can use it to mix and turn the raw materials. It takes 7-15 days for the whole composting.
This lesson is part of:
Chemistry and the Real World