Participatory design to investigate the effects of farmers’ fertilization practices under unsubmerged conditions toward efficient nutrient uptake in rainfed rice

Abstract

Rainfed agriculture plays a vital role in providing food and livelihoods globally. However, its production is adversely affected due to uncertainty in rainfall patterns causing unsubmerged conditions during the dry period, which is increasing under the impact of climate change. Given that rice is a primarily grown crop in rainfed conditions and is the staple food of half the global population, it is under pressure to increase production due to the burgeoning population globally. Therefore, proper farming management such as balanced fertilization practices, irrigation etc. are required. Thus, we studied the effect of human-induced nutrient application quantity for nitrogen (N) and phosphorus (P), on production efficiency and assessed the nutrient budget in rainfed rice fields of Jamuna command area, Assam, India. A questionnaire was developed to know the farm management practices adopted by farmers and accordingly, applied N and P doses were ranked. Low, medium, high and very high doses for N are 40–60, 61–80, 81–100, 101 kg ha−1 and above, respectively, while for P are 0–4, 5–9, 10–19, 20 kg ha−1 and above respectively. Rice plants were sampled from farmers’ field of selected thirteen villages, at the maturity stage, soils were sampled after rice harvest to analyze Total Kjeldahl Nitrogen (TKN) and available Phosphorus (Pav). Nitrogen (N) balance was positive ranging from 33 kg ha−1 to 72 kg ha−1. Phosphorus (P) balance was ranging negative from 28 kg ha−1 to 129 kg ha−1. N uptake increased in order of low<medium<very high<high doses while P increased in order of high<very high<low<medium. The findings showed that plants uptook P efficiently under unsubmerged conditions. N uptake was consistent after a fertilizer dose of 100 kg ha−1. From the quantitative measurements of nutrient uptake and Cobb-Douglas model analysis validated farmer information on fertilizer and crop yield. Results also revealed that averaging across all the villages an amount of 71 kg ha−1 is needed for P replenishment to maintain the yield along with water for increased soil moisture in lateritic soil. Finally, it is concluded that involving farmers will prevent soil deterioration in rainfed rice areas and a policy shift to develop optimal N and P management strategies for sustainable agriculture under unsubmerged soil conditions.