Nutrient Expert® for Wheat - South Asia

A user-friendly nutrient decision support tool that enables researchers, extension experts and industry agronomists to quickly develop field specific fertilizer recommendations for wheat.


Wheat is the second most important cereal crop next to rice in Asia. Wheat is grown on about 29 M ha in India with an annual production of 86 M t in 2010-11 and an average yield of 2.98 t/ha (FAI, 2012). Recent statistics show that there are considerable yield gaps between the major wheat-growing states in the country with highest yield recorded in Punjab (4.7 t/ha) and lowest in Bihar (1.95 t/ha). In addition, considerable yield gaps exist (Ladha et al., 2003) between researcher-managed optimum NPK plots and farmers’ fertilizer practices (FFP), indicating a great opportunity for increasing wheat yield and productivity through improved nutrient management practices.

South Asian agriculture is characterized by small land holdings for cultivation with high variability in plant nutrient availability between fields. However, fertilizer recommendations for crops in this region are usually done over large geographic areas that often fail to meet the overall crop nutrient requirement. Sitespecific nutrient management (SSNM), on the other hand, integrates information from different scalesto make field specific decisions on N, P and K management. Site-specific nutrient management is a set of nutrient management principles that aims to supply a crop’s nutrient requirements tailored to a specific field or growing environment. Its purpose, to (a) account for indigenous nutrient sources, including crop residues and manures; and (b) apply fertilizer at optimal rates and at critical growth stages to meet the deficit between the nutrient needs of a high-yielding crop and the indigenous nutrient supply.

There is little acceptance of SSNM by farmers beyond the on-farm trials. Apart from shortcomings in the strategy to promote SSNM, and farmer’s inability to buy fertilizers, extension agents lack confidence in using the methodology (Gabinete and Buresh, 2009). Many extension agents still perceive SSNM as complex, requiring an understanding of concepts and methods outside their experience. Such knowledge requirements have slowed the wide-scale promotion and adoption of SSNM by the farmers and extension agents (Buresh, 2008). The need for more rapid uptake of the SSNM technology by farmers led in the consolidation of SSNM research conducted over the last decade across Asia into a simple delivery system, Nutrient Expert® for Wheat, enabling wheat farmers of the region to rapidly implement SSNM for their individual fields. Nutrient Expert® is a new, computer-based decision support tool that helps crop advisers formulate fertilizer guidelines based on SSNM principles. Nutrient Expert® considers the most important factors affecting nutrient management recommendations in a particular location and enables crop advisers to provide farmers with fertilizer guidelines that are suited to their farming conditions. The tool uses a systematic approach of capturing site information that is important for developing a location-specific recommendation. Yet, Nutrient Expert® does not require a lot of data nor very detailed information as in the case of many sophisticated nutrient decision support tools, which could overwhelm the user. It allows users to draw the required information from their own experience, the farmers’ knowledge of the local region, and the farmers’ practices. Nutrient Expert® can use experimental data, but it can also estimate the required SSNM parameters using existing site information. Currently, Nutrient Expert® has been applied to wheat for South Asia and China.

The User Manual, while describing various steps involved in operating the tool, will help the user in developing an improved nutrient management practice for attaining better yields of wheat.

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