Optimizing cattle and goat manure quality to improve fertility status of fragile soils in semi-arid agrozone of Samburu County, Kenya
摘要
Expansion of intensive livestock production has led to huge amounts of livestock manure, which is a great environmental threat if not well managed. Yet, management of livestock manure in dryland and its influence on dryland agrozones remains scarcely understood. A 90-day composting trials were established to assess the effects of different composting strategies on manure quality and its effect on physicochemical characteristics of arid and semi-arid (ASAL) soils. A plot trial was laid in a randomized complete block design with the following treatments: i) Control (T1), ii) 20 t ha−1 of cattle manure from open compost pit (T2), iii) 10 t ha−1 of goat manure ash added compost pit (T3), iv) 20 t ha−1 of cattle manure from covered compost pit (T4), v) 10 t ha−1 goat manure from open compost pit (T5), vi) 10 t ha−1 of goat manure from covered pit (T6), and vii) 20 t ha−1 of cattle manure ash added compost pit (T7). Manure quality from the composting pits differed significantly. Covered pits at 50 cm depth recorded the highest Nitrate- N levels (188.0 ppm), followed by open pits at 100 cm (148.0 ppm). Goat manure stored in covered pits had significantly lower subsoil nitrate (0.13 ± 0.14) compared with cattle manure in open or covered pits (T2 and T4; 0.47 ± 0.15 and 0.47 ± 0.03, respectively). Similarly, there was significant variations on soils collected from the plot trials. Soil moisture content improved significantly from 17.08% in T1 to 23.05% in covered pits. The lowest soil bulk density was recorded under plots receiving compost from the covered pits (1.02 g/cm3). Moreover, nitrate–N at a depth of 10–20 cm (p = 0.01) showed a significant treatment effect. Covered pits improved manure quality and soil physicochemical characteristics hence, could be a sustainable management approach that enhancese soil fertility and improving agricultural productivity in ASAL soils.