Assessment of Agronomic and Economic Benefits of Fertilizer Use in Maize Production Systems under Variable Farm Size, Climate and Soil Fertility Conditions in Odisha

The current investigations studied the influence of farmer resources and management practices on maize productivity in Odisha. Farmer typologies were categorized based on the information gathered on socio-economic and bio-physical parameters collected through the rapid rural survey. The identified typologies were further used to provide farmer resource based precise nutrient recommendations. During the first phase of implementation, two districts (namely Navarangpur and Kalahandi) were selected and 20 farmers in each district were provided with Nutrient Expert^® (NE)-based fertilizer recommendations that were compared with farmers' fertilizer practice (FP) and the State recommendation (SR).

The soils in Navarangpur were sandy to sandy loam in texture, strongly acidic (pH 4.6 to 6.4), low to medium in organic C (4.2 to 8.2 g/kg soil), low to high in available P (8.5 to 149 kg/ha), medium to high in available K (137 to 384 kg/ha). The soils in Kalahandi were sandy loam to sandy clay loam in texture, moderately acidic (pH 4.9 to 7.6), low in organic C (1.9 to 5.0 g/kg soil), low to high in available P (2.5 to 211 kg/ha), and low to high in available K (92 to 265 kg/ha). In Navarangpur, grain yield of maize with NE averaged 5.7 t/ha and ranged from 4.9 to 6.9 t/ha, which was 20% higher than the SR and 38% higher than the FP. Similarly, in Kalahandi, the average maize yield with NE was 5.9 t/ha and ranged from 5.2 to 6.0 t/ha, which was 14% higher than the SR and 48% higher than FP, respectively. Also, the yield targets made using NE ranged between 5 to 7 t/ha in Navarangpur and 4 to 8 t/ha in Kalahandi, and the actual yields attained in both districts using NE were 97% of the estimated yield, indicating that NE is capable of successfully estimating the yield targets based on the identified farmer typology.

The high yield of maize observed with NE in Navarangpur is attributed to a high total nutrient uptake (NPKS) of 248 kg/ha, which was 61% higher than FP and 37 higher than SR. Similar observations were also recorded in Kalahandi where the total nutrient uptake of 213 kg/ha with NE was higher than FP and SR by 43 and 21%, respectively. The study also found a high benefit-to-cost ratio of 1.7 with NE (SR 1.5, FP 1.2), better nutrient use efficiency, and better post harvest soil properties with NE than SR and FP. Thus, NE-based fertilizer recommendation helped in improving the yield and economics of farmers as per the identified farmer typologies existing under varied soil, climate and socio-economic conditions. The study is currently extended to four new districts in Odisha and the project is ongoing for another year.