Pakistan’s economy is based on agriculture but still, Pakistan is facing a shortage of grains in the country, there is a big gap between supply and demand. Wheat is an important cereal crop worldwide as well as in Pakistan. In Pakistan, the average yield potential is much less than growing countries of the world. A deficit of wheat supply is very often in the country and Government is imposed to import wheat by allocating an enormous amount of foreign exchange. To fulfill the demand it is important to maximize the cultivation of food grains. There are different reasons of low wheat production in our country as delay in wheat sowing due to a late vocation of rice field and low availability of phosphorus (P) due to its fixation in our soils.
Application of Fertilizers
The increase in grain yield is related to an increased application of fertilizer or more truly the increased uptake of nutrients. Soil nutrient statistics important for maintaining high quality and sustainable crop production. It is very important to maintain soil nutrients at a sufficient level, to maintain optimum plant growth. Application of fertilizers is optional because their costs are too high for farmer, so high use of these fertilizers is not profitable. Almost all the soils in Pakistan have poor fertility status due to lack of organic matter and arid climate as soils developed under severe climate are poor in organic matter and nutrients like nitrogen, phosphorus and sulfur. Phosphorus (P) is one of the most important growth-limiting nutrients. Phosphorus is a naturally occurring element that can be found in the earth’s crust and all living organisms. In plants, it plays a vital role in many physiological processes such as the promotion of early heading and uniform maturity, a growth of early root and seedling, It also supports seed formation, increases seed quality and water-use efficiency. Phosphorus is also important during major biochemical processes like respiration, cell division, photosynthesis, storage and transfer of energy.
Conditions of Pakistani Soils
Most Pakistani soils are alkaline having pH > 7.0 as well as calcareous (CaCO3 > 3.0%) in nature. Phosphorus fixation is a severe problem in alkaline and calcareous soils. When Phosphatic fertilizers are applied to the soil, < 1% of it becomes part of soil solution for uptake by plants. While remaining goes to exchange sites and it is either adsorbed or precipitated. The average recovery of phosphorus fertilizer by crops is very low and varies from 15-20% on single crop basis. It is estimated that phosphorus recovery in alkaline calcareous soil is 0.02 to 0.5%. This is because of the high phosphorus fixation property of our soils. It is estimated that 80-90% of Pakistani soils fall in the range between low to medium in phosphorus concentration and high in calcareous. According to a study, Punjab province is losing phosphorus at a rate of 0.016 ppm per year. This may be attributed to reversion of applied phosphates to less available forms such as coat-calcium phosphates, carbonate apatite, hydroxide apatite and flour apatite by reacting with clay and calcium compounds. Applying good source of fertilizers may resolve this problem.
By Shoaib Aslam
