Fertilizers consumption scenario and nutrient demands

Fertilizers consumption scenario and nutrient demands

The fertilizer use in India increased significantly in the last 40 years from 9.4 kg/ha in 1967-68 to 117 kg/ha in 2007-08 which contributed to increase in agricultural production by 50 to 60%. However, there is a wide variation in use of fertilizers among states and regions and has remained concentrated in irrigated areas which constitute only 40% of the total cropped area. Among the major states, Andhra Pradesh and Punjab consume high levels of fertilizers. After remaining subdued for few years, fertilizer consumption increased since 2003-04 from 16.2 M tons to 23 M tons in 2007-08.

The fertilizer consumption varies significantly from state to state and spatially. It was >150 kg/ha in North and South zones compared to 104 and 83 kg/ha, respectively in East and West zones. Among the states, the highest per-hectare consumption is in Punjab (210 kg) followed by Andhra Pradesh (200 kg) (Table)

Out of 466 districts, 25% of total fertilizer use is consumed in 37 districts, 50% in 102 districts and 75% in 202 districts. In 65% of districts less than 100 kg nutrients/ha are used, 100-200 kg/ha in 28%of districts and more than 200kg/ha in only 7 per cent of the districts. Consumption ratio of primary plant nutrients (NPK) also shows large variability (FAO, 2005). Regionally the consumption of nutrients in north zone acutely skewed towards N in relation to K (103:32:5.3 kg NPK/ha) compared to south and east zone (60:26:19 and 49:16:11 kg NPK/ha, respectively) while it is more serious at the state and district levels.

Fertilizer use has been increasing more so in the irrigated systems from 65 % of the total in 1986-87 to 75 % in 2000-02, and with increasing use of HYVs. Bulk of the fertilizers (nearly 72 %) is used for food grain crops, 9% for oil seeds followed by sugarcane (5%), vegetables (4%), spices and cotton (3 % each) and fruits (2%). Major share is accounted for paddy (37%) and wheat (24%) among food crops. On an average farmers applied 126 kg/ha of NPK to rice in 2001-02 in the ratio of 4.3: 1.7: 1. In irrigated areas it was about 165 kg/ ha for paddy and 132 kg/ha in the ratio of 24:10:1. Under rice-wheat cropping system, the per-hectare consumption of nutrients in the IGP on an average is about 334 kg (range 258 to 444 kg) approximately @ 118, 36 and 11 kg/ha for each crop which show a decreasing trend west to east.

Nutrient demands Indian agriculture is operating at an estimated negative nutrient balance of 10.0 M tons per year of NPK which is likely to increase. Nutrient use of 23 M tons in 2007-08 is expected to increase to 29 .0 M tons (20.7 N, 6.8 P205 and 2.1 K2O M. tons). At an estimated nutrient removal of 37.5 M tons of NPK (11.9 N + 5.3 P2 05 + 20.3 K2O M. tons) the nutrient balance indicate excess use of N and P205, and deficit use of nearly 18 M tons of K (Table) which accounts for 55% of NPK removal. The demand for NPK to meet food production by 2025 would be about 30 M t. and another 15 M t, for commercial crops.     No single source can meet such a huge demand for fertilizers. This can be only tackled by integrated use of all nutrient sources. However, Indian soils are estimated to be losing about 9 Mt of N, P2 O5 and K2O annually even after harnessing currently utilizable organic sources and through BNF on gross basis (Tandon, 2004). At the current rate of population growth and net cropping land, annually NPK consumption should increase by 0.55-0.60 Mt at an agronomic efficiency of 8 kg grain/kg nutrient applied when two third of fertilizer is used for food grain production. Each ton of cereal removes about 82 kg of plant nutrients out of which 75% is accounted by NPK. However, assuming stagnant soil nutrient supply, each extra ton of cereals would demand 100 kg NPK at response ratio of 10:1 and 125 kg at 8:1 response ratio or on an average @ 0.6-0.7 Mt annually to produce food and fiber. This should also include S and Zn considering projected uptake of 2.4 Mt of S by 2012.