Soil fertility, the capacity of soil to support plant growth and maximize crop yield, is a critical component of sustainable agriculture. However, soil fertility is currently under threat due to various factors including intensive agricultural practices, climate change, and indiscriminate use of chemical fertilizers and pesticides. These practices lead to soil degradation, nutrient depletion, erosion, and loss of organic matter, significantly diminishing the soil’s productive capacity.
Recognizing these challenges, soil fertility management becomes essential. It involves adopting practices that restore soil health, improve its structure and capacity to retain water and nutrients, and enhance its biodiversity.
Causes of reduction in Soil fertility
- Soil Erosion
- Removal of nutrients by crops
- Reduction in soil organic matter
- Leaching of nutrients
- Intensive cropping system
- Improper crop rotation
1. Soil erosion
When nutrients from the upper surface of the earth are moved from one place to another by wind or water, it is called soil erosion. Soil erosion by wind happens when we leave the land open by ploughing, and soil erosion by water happens when we apply more water or when there is more rain, nutrients dissolve in water and break down. They move from acre to acre
2. Removal of nutrients by crops
When we plant a crop on the ground and when it is ripe and ready, then we cut it and the nutrients that were transferred from the ground to the crop will become deficient in these nutrients in the ground, so this means the removal of Nutrients by crops is also one cause of reduction in soil fertility
3. Reduction in soil organic matter
The reduction of organic matter in the soil is also a factor which reduces the fertility of the soil. Due to the high temperature in the tropical region, the organic matter depletion rate is high. Bacteria in the soil convert organic waste in a certain temperature range. When the temperature is high, the rate of depletion of organic matter is also high.
4. Leaching of nutrients
When we water the land or when it rains, the soluble nutrients are leached. This happens because when the land is cultivated more, the pore spaces increase it, which leads to the leaching of nutrients, for example, nitrates and sulphates.
5. Intensive cropping system
When we plant one crop after another and do not give the soil a break, the soil becomes depleted of nutrients. For example, after the rice harvest, potatoes are cultivated and after that, they are cultivated maize. Long-term productivity is reduced by an intensive cropping system.
6. Improper crop rotation
We are not doing proper crop rotation either we are planting all restorative crops or we are cultivating all exhaustive crops. If we plant all the exhaustive crops, then this land will lack nutrients. And if all the restorative crops are planted, nutrients will be wasted. A good crop rotation also means that an exhaustive crop should be planted after a restorative crop, which can maintain the fertility of the land.
Volatilization also reduces the fertility of the land. Most of the farmers are applying fertilizers without water during the sun, which causes the volatilization of nutrients. Also, if you are not planting any crops, the residue spreads on the land. so that volatilization is minimized
When there is standing water on land or there is a lot of rain in an area, salt comes to the surface of the land, which affects the growth of plants and also reduces the fertility of the land.
Where there are forests, the land is more fertile, while our forests are being cut, which is increasing the reduction fertility of the land.
Management of reduction in Soil fertility
Add compost to the soil
Compost provides slow-releasing nutrients which increase soil quality dramatically.
Compost enhances the process of soil humus production. You can recycle almost any organic waste to sawdust. compost will reduce the bulk of waste and convert it into valuable and soluble nutrients
Cover crops can feed garden soil buildup. Its quality also improves its structure with each passing Year. Channels opened up by cover crop roots help oxygen and Water to enter the Soil. Different families of crops are grown together for their effectiveness. Divide your farm into parts, Some parts of the farm should grow and cover crops and some parts of the farm should grow food crops and them every year
Use of dung to compact the soil. Use manure from homesteads or small forms they tend to have fewer pathogens than those that have large firms. It is best for fast-growing crops. One thing to remember is that when you apply dung, do not plant the crop immediately after it, but after two to three months.
Plant the crops that have deep roots so they can better absorb nutrients and produce better yields
Biological pest control method
Pests should be controlled biologically, for example, chickens should be released on the ground to feed on pests that may be harmful to the crop.
Mulching should be done by which the moisture of the soil is maintained and the soil is protected from erosion. There are many types of mulching. One is done with crop residue and the other is also done with a plastic sheet. By which the fertility of the land can be maintained
Minimum tillage practice to maintain the fertility of the land. The more you plough, the chance of waste of nutrients will increase, so plough as little as possible. Modern tillage practice should be adopted for example zero tillage
Avoid overuse of fertilizer, pesticide
Don’t overuse fertilizers and don’t overuse pesticides, but organic fertilizers and biological pests should be controlled so that the fertility of the land can be maintained.
Add biochar to the soil
Add biochar to the soil which increases the water-holding capacity of the soil and also increases the fertility of the soil.
Conservation of water
Water should be used in a better way, which can reduce the wastage of nutrients, and modern technological methods should be adopted, such as drip irrigation, sprinkler irrigation systems, etc.
Avoid heavy machinery
Heavy machinery should not be used on the land either during cultivation or harvesting. Using heavy machinery hardens the soil and reduces the microbial activity in the soil, which reduces the fertility of the soil.
In conclusion, it is crucial for countries with agricultural sectors to prioritize the preservation and enhancement of land fertility. The fertility of the land directly impacts food security and the ability to meet the growing demands for food. Governments should focus on providing farmers with the necessary knowledge and resources to improve land fertility through education, training, and access to modern agricultural practices.
By promoting sustainable land management techniques and investing in agricultural research and development, countries can ensure a consistent and abundant food supply while mitigating the adverse effects of land degradation. It is essential to recognize the value of fertile land and take proactive measures to maintain its productivity for the benefit of present and future generations.
Ghulam Mustafa, Ghulam Murtaza
Department of Agronomy, University of Agriculture Faisalabad