Better Nutrient Management Improves Incomes for Indian Rice-Maize Farmers

With 100 million tons grown in 2011 alone, rice is traditionally the grain of choice in India. Nowadays, however, farmers are increasingly choosing to diversify their produce and supplement their income by growing maize in the same fields as rice each year (during the winter season). Supplementing rice with maize allows farmers to increase the productivity of their land and brings the added benefits of a greater resistance to bad weather and pests.

On the downside, maize also uses up more nutrients in the soil than either rice or wheat. Alongside improper fertilizer use, this has unfortunately contributed to an imbalance and lack of nutrients in the soil. With a resulting overall decline in farm productivity, there is a strong need to increase yields of rice and maize to help ensure food security for India’s growing population. Between 2013 and 2016, a joint project between the International Plant Nutrition Institute (IPNI) and Rajendra Agricultural University was carried out in two districts in Bihar state, Samastipur and Muzzafarpur, to measure the benefits of single and combined nutrient use in mixed rice-maize fields.

Twenty-five Farmers took part in field trials to compare rice and maize yields using the recommended applications of Nitrogen (N), Phosphorus (P), Potassium (K), Sulphur (S) and Zinc (Zn) against plots where no additional nutrients were added. Thanks to their experiments, they were able to see firsthand, in their own fields, proper nutrient management bringing impressive increases in both yields and profitability.

The combined relative yields of both rice and maize was highest following a complete fertilizer application of N, P, K, S and Zn. When N was left out the yield almost halved, with a decrease of 48%. Omitting any of the other nutrients also caused yield losses. In comparison, the relative yields on the unfertilized plots were 58% lower than on the fully fertilized plots.

Combined yield of rice and maize with full fertilization, compared with the omission of a single nutrient or all nutrients (control). Yields expressed as Rice Equivalent Yield, REY

The loss of economic value of rice and maize caused by omitting a single plant nutrient, compared with the economic return from crops receiving all of the nutrients.

From an economic standpoint, fertilizer use brought considerable benefits. Applying N boosted potential profits by $470/ha for rice and $930/ha for maize. Other nutrients added between $80/ha and $290/ha, showing that they all contributed to improving productivity. With training and field days organized for over 100 neighbouring farmers, the study clearly showed local farming communities the advantages of using balanced fertilization on rice-maize rotations. As Dr. Sudarshan Dutta, Deputy Director IPNI South Asia Program observed: “Through a combination of research results, farmer training, field visits and dialogue between farmers and scientists, the project was a very effective way to raise awareness about improved nutrient management practices in the rice-maize cropping system.”

Read more about the project here.