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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Feeding, crop residue and manure management for integrated soil fertility management
T2 - a case study from Kenya
AU - Castellanos-Navarrete, A.
AU - Tittonell, P.
AU - Rufino, M. C.
AU - Giller, K. E.
PY - 2015/3
Y1 - 2015/3
N2 - Western Kenya is one of Africa's most densely populated rural areas, characterised by intensive smallholder crop-livestock systems on degraded lands managed with small inputs of mineral fertiliser and animal manure. Competing uses for crop residues and other organic resources often results in poor nutrient cycling efficiencies at farm scale. Modifying livestock feeding, retaining more crop residues in the field, and improving manure management can help conserving considerable amount of nutrients on-farm. To examine to what extent such strategies would be feasible, we analysed whole-farm nutrient cycling efficiencies (NCE) of a range of farms differing in resource-endowment and production orientation, identifying the most efficient farmer strategies considering labour and financial constraints. Nutrient concentration in excreted cattle manure was relatively small (i.e., N <1.7%; P <0.6%). Current manure management practices led to low NCE's (average 27%) due to nutrient losses from excretion through storage and application. Farmers have few incentives to improve manure management given the small amounts of excreta and nutrients to be recycled. Yet, manure, both composted and fresh, represented the greatest N (16 kg ha(-1) season(-1)) and C returns to the soil (312 kg C ha(-1) season(-1)). Retention of crop residues was the cheapest source of nutrient inputs for the next crop, especially when compared with manure, but farmers prioritised its use for cattle feeding. Our findings highlight the critical lack of nutrients and organic residues on smallholder farms in the densely-populated highlands of East Africa, as well as low NCE when it comes to manure. In these conditions, efficient nutrient cycling for manure and improved cattle feeding are essential to increase use efficiencies of any possible external nutrient added in these farms. (C) 2014 Elsevier Ltd. All rights reserved.
AB - Western Kenya is one of Africa's most densely populated rural areas, characterised by intensive smallholder crop-livestock systems on degraded lands managed with small inputs of mineral fertiliser and animal manure. Competing uses for crop residues and other organic resources often results in poor nutrient cycling efficiencies at farm scale. Modifying livestock feeding, retaining more crop residues in the field, and improving manure management can help conserving considerable amount of nutrients on-farm. To examine to what extent such strategies would be feasible, we analysed whole-farm nutrient cycling efficiencies (NCE) of a range of farms differing in resource-endowment and production orientation, identifying the most efficient farmer strategies considering labour and financial constraints. Nutrient concentration in excreted cattle manure was relatively small (i.e., N <1.7%; P <0.6%). Current manure management practices led to low NCE's (average 27%) due to nutrient losses from excretion through storage and application. Farmers have few incentives to improve manure management given the small amounts of excreta and nutrients to be recycled. Yet, manure, both composted and fresh, represented the greatest N (16 kg ha(-1) season(-1)) and C returns to the soil (312 kg C ha(-1) season(-1)). Retention of crop residues was the cheapest source of nutrient inputs for the next crop, especially when compared with manure, but farmers prioritised its use for cattle feeding. Our findings highlight the critical lack of nutrients and organic residues on smallholder farms in the densely-populated highlands of East Africa, as well as low NCE when it comes to manure. In these conditions, efficient nutrient cycling for manure and improved cattle feeding are essential to increase use efficiencies of any possible external nutrient added in these farms. (C) 2014 Elsevier Ltd. All rights reserved.
KW - Crop-livestock interactions
KW - Feed
KW - Manure
KW - Mulching
KW - Nitrogen cycling efficiency (NCE)
KW - Soil fertility
KW - SMALLHOLDER FARMING SYSTEMS
KW - WESTERN KENYA
KW - CONSERVATION AGRICULTURE
KW - LIVESTOCK SYSTEMS
KW - CYCLING EFFICIENCIES
KW - EXPLORING DIVERSITY
KW - CARBON DYNAMICS
KW - DAIRY-COWS
KW - HIGHLANDS
KW - RESOURCE
U2 - 10.1016/j.agsy.2014.03.001
DO - 10.1016/j.agsy.2014.03.001
M3 - Journal article
VL - 134
SP - 24
EP - 35
JO - Agricultural Systems
JF - Agricultural Systems
SN - 0308-521X
ER -