SITE-SPECIFIC NUTRIENT MANAGEMENT (SSNM)

Background

Existing fertilizer recommendations for rice often consist of one predetermined rate of nitrogen (N), phosphorus (P), and potassium (K) for vast areas of rice production. Such recommendations assume that the need of a rice crop for nutrients is constant over time and over large areas. But the growth and needs of a rice crop for supplemental nutrients can vary greatly among fields, seasons, and years as a result of differences in crop-growing conditions, crop and soil management, and climate. Hence, the management of nutrients for rice requires a new approach, which enables adjustments in applying N, P, and K to accommodate the field-specific needs of the rice crop for supplemental nutrients.

What is the site-specific nutrient management approach?

The site-specific nutrient management (SSNM) approach was developed in Asian rice-producing countries through partnerships of the Irrigated Rice Research Consortium (IRRC). It emphasizes ‘feeding’ rice with nutrients as and when needed. SSNM strives to enable farmers to dynamically adjust fertilizer use to optimally fill the deficit between the nutrient needs of a high-yielding crop and the nutrient supply from naturally occurring indigenous sources such as soil, organic amendments, crop residues, manures, and irrigation water. The SSNM approach does not specifically aim to either reduce or increase fertilizer use. Instead, it aims to apply nutrients at optimal rates and times to achieve high yield and high efficiency of nutrient use by the rice crop, leading to high cash value of the harvest per unit of fertilizer invested.

The SSNM approach can be described in three basic steps.

Site Specific Nutrient Management