Punjab has the highest food grain yield in the country and this started with the green revolution. The initial increase in agricultural production in the state was mainly due to increase in net sown area. However, the huge rise in food grain production can be largely attributed due to intensive use of farm chemicals. High usage of nitrogenous fertilizers and under –utilization of other fertilizers & micro-nutrients has lead to imbalance in micro-nutrients in soils of Punjab. The various studies undertaken in the state since 1970 indicated the presence of residues of chemical pesticides like organochlorines, organophosphates, synthetic pyrethroids and carbamates in human beings, milk, vegetables and other food products at level, which are unsafe to human health. Non-judious use of pesticides has also resulted in the development of pesticide resistance in various insects and pests. The pesticide consumption in the state has been decreasing since 2000-01,which could be due to the introduction of Bt. Cotton (which requires less sprays) as well as, better awareness among farmers.
Trends in Fertilizer & Pesticide Use in Punjab
The trends of fertilizer use in Punjab show that the fertilizer use in the state increased tremendously from 37.5 kg per ha in 1970-71 to 162.6 kg per ha in 1990-91 to 243 kg per ha in 2010-11. Further, in 2018-19, the fertilizer use came down to 228 kg per ha.
Source: Economic and Statistical Organisation, Punjab and Agricultural Statistics at a Glance, 2018
The comparison with national average fertilizer use data shows that the per hectare use of fertilizer in Punjab was more than twice the average used in India in 1990-91. Further, in 2010-11, this ratio was 1.67, as all India average use of fertiliser per hectare also increased. Between 2011-12 and 2013-14, the ratio again started rising, as average use at all India level dropped. Further in 2017-18 (the latest year available data), the ratio between Punjab State and the country was 1.77.
The overuse of fertilizers results in imbalance of soil nutrients which in turns affects the plant growth & crop yields. The low availability of particular nutrient leads to hampered growth and low yields, while too high availabilities of one or more nutrients may lead to disturbed plant growth and adverse effects for yield and/or quality of harvested products. The right content of Nitrogen, Phosphorus and Potassium (NPK) in soil is very important and should be sufficient for good crop yield. Ideally, the NPK consumption ratio in soil should be 4:2:1. But in Punjab the unscientific use of NPK nutrient ratio (increased the nitrogen content in Punjab soils) has an adverse impacts on nutrient elements in the soil. During 1990-91, the NPK consumption ratio was 58.5:21.9:1 and in 2017-18, it was 28.8:6.9:1 but it has shown significant improvement during 2018-19.
The pesticide use in the state has decreased over the years. The pesticide use was high (6970 metric tonnes) during the year 2000-01 and has been reported to be around an average of 5717 metric tonnes, since 2011-12. The high usage was reported in 2016-17 due to the pest attack in the previous year and further in 2018-19, the pesticide use declined by 0.7 percent over the previous year.
Source: Directorate of Agriculture and Farmers Welfare, Punjab s cited in Statistical Abstract 2018