Nutrient management reduces fertiliser use

Saturday, February 07, 2009

By Jawwad Rizvi

LAHORE: Importance of managing fertiliser input techniques have increased in a scenario when international commodity prices are dropping and prices of nutrients are rising. The field crop costs are rising daily. Field crops require adequate nutrients for producing good yields and desirable quality.The agriculturalists using latest farming technique to increase per acre yield said the crops grown with adequate nutrient levels will also mature sooner. Farmers using the artificial methods to control weather and producing early crops said it was possible to optimise fertiliser inputs by adopting different modern techniques.Naseem Haider a modern framer says soil testing was the basis for good fertilizer management. Using fertilizer to meet crop needs is more profitable than feeding the soil, he remarked.Soil testing allows crop producers to compare field fertility levels against the probability that adding any one nutrient will increase crop yields in that field. However, there is need of extensive soil survey by the government as the farmers are unaware of such modern techniques. On the basis of results obtained from the soil survey the government suggest the farmers which nutrients are currently need and which should not be use to increase productivity, Naseem mentioned.Naseem observed that managing nutrient timing and placement could also optimise fertilizer use. Placing phosphorus with or very near the seed of annual crops is best because plants absorb and use most of this nutrient at their initial growth stages. He said yields were best when phosphorus was absorbed into plant tissues early. Phosphorus fertiliser is not available to plants when applied too late or too far from roots.Testing irrigation water is another way to optimise fertilizer efficiencies, said Mian Hanif a seasoned agriculturists. Mostly nutrients exist in irrigation water to meet the crop needs even, he said.Laboratory tests have shown that irrigation water particularly ground water often has adequate amount of sulphur and boron. Similarly, irrigation water may also meet part of nitrogen requirements of the crop. In such cases there was no need to use such nutrients, he said adding excess use of such nutrients was bad from crops. Setting a realistic crop yield goal is important for managing nitrogen fertilizer inputs. The best fertilizer input for increasing irrigated corn profits are usually from nitrogen because this nutrient is nearly always deficient in soils. Nitrogen fertilizer recommendations are based on crop yield goals, soil and water test levels, previous crops and manure applications. Shahid Mobeen an agriculturalist from sindh said nitrogen is absorbed and used during plant growth so the nitrogen fertilizer should be made available when plant growth rates begin to peak. He further said managing irrigation was also critical for fertilizer optimisation. Nitrogen leaching is a problem on sandy soils, especially if it is applied in high amounts before crops begin their rapid growth phase. Irrigation in the spring also cools soils reducing plant root growth and nutrient absorption.Shahid suggested frequent spring irrigation to reduce phosphorus uptake by plants through soil cooling. Reducing fertilizer losses and cool soil absorption problems through good irrigation practices and optimum nutrient placement and timing could reduce the cost of production of farmers.