Measuring SSNM impact in the Red River Delta

Site-specific nutrient management (SSNM) has been introduced for five years now in the Red River Delta in North Vietnam, probably one of the most intensively cultivated agricultural areas in the world in terms of both cropping intensity and the collective amount of grain produced each year. To assess the performance of SSNM in terms of farmers’ productivity, income, and socioeconomic welfare, the Irrigated Rice Research Consortium (IRRC), in collaboration with Hanoi Agricultural University No. 1 (HAU 1), conducted impact assessment surveys from 31 July to 13 August 2007.

The survey was done in Hanam and Hatay, two of five provinces in the Red River Delta where SSNM evaluation and nutrient omission plots were conducted in five soil types. The survey team was composed of 11 faculty members and four students from HAU 1, a faculty member from Vietnam Forestry University, and a researcher from the Research Institute of Fruit and Vegetable. IRRC agricultural economist Divina Gracia Rodriguez led the team along with Dr. Nguyen Thi Duong Nga from HAU 1.

The survey team goes over the questionnaire with Dr. Nguyen Thi Duong Nga (left) of Hanoi Agricultural University No. 1.

A total of 374 farmers were randomly selected for the survey. Two sets of data were collected; knowledge, attitude, and practices (KAP) and the input-output aspect of production for two seasons of rice production (summer 2006 and spring 2007).
Among all respondents, 61% adopted SSNM. Preliminary results showed that SSNM increased rice yields significantly by 0.16 ton per hectare using significantly less nitrogen (N) fertilizer and no increase in labor as compared with traditional farmers’ fertilizer practices (FFP). SSNM farmer-adopters reduced the rate of N and potassium (K) applied by 6.1 kilograms and 4.0 kilograms per hectare, respectively, and increased their phosphorus (P) rate applied by 2.5 kilograms per hectare. This suggests that, with the SSNM approach, NPK use efficiency increased as evidenced by more grain yield per unit of fertilizer NPK used.

Mr. Thoai, a faculty member from Vietnam Forestry University, interviews a farmer on her input use, production, expenses, and income from rice farming.

However, this did not necessarily mean reduced input cost. The total fertilizer cost of SSNM adopters was still comparable with that under FFP (a difference of only US$8). Nonetheless, the increase in yield contributed to higher gross returns over total fertilizer cost of SSNM adopters ($28 increase per hectare). In addition, farmers practicing SSNM reduced their use of pesticides, which included herbicide, fungicide, and insecticide applications.

Thus, based on initial findings, SSNM adopters seemed to profit more than nonadopters. The results are, however, still preliminary because other factors of production such as seeds, pesticides, and labor are not yet accounted for. Moreover, a simple comparison of means has inherent limitations.

The benefits derived by farmers from SSNM depend on how much rice yield can be increased with improved nutrient management; the scope for further optimizing the amounts and timing of fertilizer N, P, and K to achieve such increased yield; and what related advantages there are (e.g., reduced use of pesticides). The added benefits (in terms of increased yield) from using SSNM suggest that it should be evaluated in other areas of the Red River Delta.

Story and photos by
Divina Gracia Rodriguez (d.p.rodriguez@cgiar.org)

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