The low average maize yield in the state of Odisha is associated with nutrient-depleted lateritic soils, high monsoon rainfall variability coupled with the absence of irrigation, sub-optimal plant population, and poor knowledge of modern agronomic practices. Overall, many different stakeholders, including state government, input dealers, seed companies, development partners, and farmer producers’ groups need to develop a complementary partnership to support and promote the investments and interventions needed for sustainable maize cultivation including value chain and integrated marketing in these rainfed areas.
India is the sixth-largest producer of maize in the world, and maize contributes 10% to the Indian dietary energy supply. In India, maize is the third most important crop after rice and wheat, grown on 9.0 million hectares with broad adaptability to many soil types and agro-climatic conditions. During the monsoon season in the plateau region of Odisha, rice is grown in the lowlands of the landscape toposequence with maize and other grain staples grown in the uplands. In the rainfed uplands, a common cropping system is maize followed by short-duration mustard (Brassica juncea L.) if residual moisture is sufficient and then a long fallow period during the dry season.
The average maize yield in Odisha is low; 2.2 Mg/ha with hybrids and 1.3 Mg/ha with open-pollinated varieties. This low productivity is associated with nutrient-depleted lateritic soils, high monsoon rainfall variability coupled with the absence of irrigation, sub-optimal plant population, and poor knowledge of modern agronomic practices. Due to low productivity, a large fraction of the uplands in the region is uncultivated during the monsoon (kharif) cropping season. Nevertheless, rice cultivation in the lowlands is also a risky proposition in this region. As a result, crop diversification in upland areas in the region could be a possible option in this ecology.
Various socio-economic and agronomic factors contribute to yield gaps, i.e., the difference between water-limited potential yield in rain-fed systems and average actual yield. The production factors in the rainfed upland areas in eastern India are analogous to the rainfed hill ecologies of Nepal where the adoption of best management practices (BMPs) increased grain yield by 4.5 Mg/ha. Decomposing yield gaps based on individual technology or management practices are essential because farmers rarely adopt full technology packages and entry points for intensification have different investment costs, expected benefits, levels of risk, and enabling conditions that facilitate adoption such as the level of market integration.
Among the factors contributing to maize yield gaps, sub-optimal plant populations often have a strong influence on maize productivity. However, the plant population and yield relationship are highly variable and can be affected by the maize variety, rainfall, soil fertility, and agronomic practices.
For instance, an increase in plant population without other best agronomic practices may reduce yield, especially in rainfed situations. Also, in rainfed situations, weed competition is often a serious problem with yield losses of up to 50%. The non-availability or high cost of labor for manual weeding during critical maize growth stages provides strong incentives for mechanical and herbicide-based weed control methods.
In Odisha, farmers typically cultivate maize with intensive tillage that causes soil erosion, deteriorates soil physical quality, and decreases organic carbon and soil moisture – factors that can contribute to low crop productivity. Therefore, conservation tillage (strip-tillage) may have relevance for rainfed maize in the nutrient and water-depleted plateau soils of eastern India. Several studies suggest that conservation tillage is also energy, water, and labor efficient.
Moreover, conservation tillage helps maintain soil quality, enables timely sowing with less labor, and may increase interannual yield stability in rainfed production systems. Nevertheless, the effect of strip tillage on maize productivity and profitability in the plateau region of eastern India has not been studied.
Furthermore, generalized soil fertility management practices fail to account for the high degree of condition-specificity required for productive nutrient management. For this reason, Site-Specific Nutrient Management (SSNM) approaches have been developed to enable the precision management of organic and inorganic sources of fertility. Based on the principles of SSNM and experiences drawn from several years of on-farm research on maize, the International Plant Nutrition Institute developed the decision support system tool-Nutrient Expert (NE) for maize in collaboration with the International Maize and Wheat Improvement Centre (CIMMYT) and national agricultural research and extension systems partners in South Asia.
NE for maize is a computer-based software that generates fertilizer recommendations based on farmer-elicited information on agronomic factors, nutrient management practices, and achieved crop yields from the previous year.
There is a lack of field experiments on the role of maize hybrids and agronomic practices in narrowing the maize yield gap in the plateau region of Odisha. Therefore, three types of field experiments were conducted in our study in 2013 and 2014 to explore the contribution of maize hybrids and agronomic practices to narrowing the maize yield gaps.
These experiments evaluated (1) the effect of single (individual agronomic practice) and a combination of agronomic practices (Experiment I); (2) the performance of maize hybrids with different maturity classes under BMPs (Experiment II); and (3) different nutrient (macro and micronutrients) management practices under BMPs (Experiment III).
In regions where there is only one cropping season, as in the plateau in Odisha, narrowing the yield gap through the intensification of maize during the monsoon season is essential for improving the food security of small farmers.
Our results demonstrated a tremendous scope for narrowing the yield gap through the adoption of BMPs such as long-duration hybrids, increased plant population using seed drills, site-specific nutrient management recommendations, and herbicides-based integrated weed management to control weeds either independently or in combination. For example, our results showed that the yield gain from the three experiments ranged from 1.7 to 4.0 Mg/ha under a combination of BMPs and hybrids.
All these BMPs also increased profitability, an important determinant of the adoption of these practices. The profitability gain was USD 559/ha USD 885/ha, and USD 314/ha due to the adoption of a combination of BMPs (Experiment I), long-duration hybrids with BMP (Experiment II), and NE-based fertilizer recommendation (Experiment III), respectively.
Overall, many different stakeholders, including state government, input dealers, seed companies, development partners, and farmer producers’ groups need to develop a complementary partnership to support and promote the investments and interventions needed for sustainable maize cultivation including value chain and integrated marketing in these rainfed areas.
Read the study:
Peramaiyan P, McDonald A, Kumar V, et al. (2022) Narrowing maize yield gaps in the rainfed plateau region of Odisha. Experimental Agriculture, 58, E18.