Mixed System, External Feed
Environmental Risks and Opportunities: (intensification)

This table indicates the most common environmental risks and opportunities associated with the mixed system based on the use of external feed.

Problem Area | Risks and Opportunities | Underlying factors
Land: | (-) Soil mining of area of feed origin (-) Point pollution with plant nutrients: Nitrogen, Phosphorous, Potassium (N;P;K) (+) Maintenance / rehabilitation of soil fertility and structure of land under cultivation. (-) Accelerated decline soil fertility and sheet erosion on further away fields | Increased trade and transport opportunities. Increased processing of agricultural products at industrial level. Increasing market demand for animal products. Skewed livestock / land ratio, poor manure collection and storage facilities. Surplus of plant nutrients from livestock compensating exports through crops, respectively facilitating the rehabilitation of degraded land. Repeated cultivation with insufficient manure supply. DAP facilitating an expansion of area under cultivation, shorter fallow and longer cultivation periods
Water | (-) Ground and surface water pollution with Nitrogen and Potassium from manure; feed additives and residues from pest control (-) pollution of water sources with faeces, urine and dirt (-) pollution of water woth agro-chemicals | Large numbers of high productive animals result in high levels of residues from feed and from pest and hygiene control in affluent farm production units Poor management of animal wastes Increased competition for water for human needs, livestock and irrigation Increase in irrigated agriculture and use of agro-chemicals
Air | (-) Methane and Ammonia emissions from manure (-) increase in Methane(CH4) emission | Feed with a high digestibility and protein content results in easily degradable manure and urine with a high Nitrogen content. More carbohydrates decomposed by livestock less by wild and soil life or through burning.
Vegetation | (+) Reduced risk of overexploitation | External feed as alternative in times of poor supply of local feed.
Bio-diversity | (-) Relies in longer term on species genetic diversity in less intensive systems (-) Loss if genetic diversity in domesticated species | Narrow genetic base of breeds selected on production in intensive systems for generations. Loss of diversity in ecological and socio-economic settings in which animals are kept

> > [Livestock & Environment Toolbox Home]