Organic methods of production can sustain soil fertility and increase crop yields.
Soil is one of the most important resources on the farm, both in crop and even in animal production. Unless farmers take good care of the soil, their crops and even pasture cannot give them the desired yields and income. The problem is that although every farmer wants to get the highest yield possible, they forget that good crop yields can only be obtained if they maintained soil fertility through proper management, which helps maintain the nutrient balance in the soil.
Inorganic fertilizers cause soil acidity
It is now the beginning of the year. Many farmers will be preparing their land in time for planting. But the only input most of them will think about when it comes to soil fertility is the use of chemical fertilizer. But what they may not know is that the use of such fertilizer will only help the crop to grow in that particular season; the use of chemical fertilizer over a long period of time contributes to the build up of soil acidity– many crops including maize, which is widely grown in the country cannot do well in acidic soils, a reason why many farmers record low crop yields despite using increased amounts of fertilizers.
Feed the soil, not the plant
Organic farmers use the maxim: Feed the soil to feed the plant; the meaning of this statement is simple: When farmers build the soil fertility over a period of time, say 3 years, using organic matter such as recycling of crop residue, compost, liquid manures, crops rotation etc., all the major soil nutrients that are taken up by plants or lost through soil erosion are replaced naturally thus maintaining soil fertility. Organic farming lays the foundation of soil fertility in all types of soil. The importance of organic soil fertilization is illustrated by the use of the simple diagram given in the first column.
From this diagram it is clear that organic matter is an important part of the soil (crop residue such maize stalks, bean residue, grasses etc.) that includes living microorganisms, control both the chemical composition and the physical structure of the soil. The more organic matter is used in farms, the better the soil becomes. Farmers who add organic matter to the soil every year will notice a gradual increase in crop yields because the organic matter helps increase the nutrient level in the soil, and therefore fertility.
If chemical fertilizers are used year after year, the nutrients balance in the soil is interfered with, leading to a situation where you have more of one nutrient that blocks the others from being taken up by plants; for example, too much magnesium in the soil can block the uptake of potassium while the presence of more potassium can block the release of magnesium for use by plants –in the same way that excess nitrogen can block the availability of potassium and copper to plants.
Avoid use of chemical fertilizers
Since farmers cannot be able to tell what nutrients are missing in their soils unless they do soil tests, the easiest way is to ensure their soils have adequate organic matter at all times. Another option is to avoid the overuse of chemical fertilizers. These practices help to regulate the nutrient balance in the soil when combined with other sustainable agriculture practices such as addition of compost, manure, planting fertilizer trees, crop rotation, inter-cropping maize with beans and other legumes, planting cover crops and ensuring permanent soil cover to prevent soil erosion. The table below helps farmers decide which material to use to increase soil fertility.