Farmers dependency on forests for nutrients transfer to farmlands in mid-hills and high mountain regions in Nepal (case studies in Hemja, Kaski, Lete and Kunjo, Mustang district)

Abstract

The study assessed NPK (Nitrogen, Phosphorus, Potassium) transferred through litter from forest to farmlands, forest product extraction systems and farmers' perceptions on forest dependency for maintaining farm fertility in Lete and Kunjo, Mustang (high mountain) and Tibrekot, Kaski (mid-hill region), Nepal. NPK in composite samples of forest litter were determined by standard methods. Questionnaire survey of randomly selected households (HH) (25% of 138 in Mustang and 14.15% of 212 HHs in Kaski), key informant survey and field observations were conducted to solicit socioeconomic and resource use information. In Lete, each HH collected 582 kg Pinus wallichiana needles, made compost and transferred 3.84, 0.54 and 2.99 kg N, P and K to 0.7965 ha whereas in Kunjo, each HH collected higher (2162 kg) which transferred 19.66, 1.84 and 10.39 kg respectively to 0.55 ha farmlands per year, indicating higher dependency of Kunjo farmers for maintaining soil fertility. Forest product extraction was regulated by a local Conservation Area Management Committee consisting of ward representatives and Mukhiyas. All HHs depended on forest for maintaining soil fertility with 85.29% totally depending on forest while 14.71% also used some chemical fertilizers. In Hemja, each HH collected 250 kg leaf litter of mainly Schima-Castonopsis and transferred 11.08, 1.26 and 5.86 kg of N, P and K respectively, and 612 kg grass, transferred 16.27, 2.22 and 11.42 kg respectively per year to farmlands (0.1538 ha upland-Bari and 0.2383 lowland-Khet per HH). The litter and grass collection was regulated by operational plan and constitution of Tibrekot Community Forest. In both regions, peoples' dependency on forest resources was decreasing (according to 73.5% HHs in Mustang and 60% in Kaski) because of change in lifestyle and decrease in dependency on agriculture and livestock. Detailed study regarding effects of removal of leaf litter/grass on the functional aspect of forest ecosystem in the Nepalese context is recommended.