Nutrient Management

Knowledge Nuggets

• Soil fertility can be affected by pasture utilization and manure distribution patterns of grazing cattle. Management to keep manure evenly distributed in a pasture to maintain soil fertility lowers pasture costs and improved productivity.

• The challenge to a producer is to maintain soil nutrients at or near optimum levels for as great a part of the pasture as is economically feasible. The choice of the forage-livestock management system can have a profound impact on the efficiency of nutrient return to grazing lands by the grazing animal.

• Livestock excrement represents a valuable, recyclable source of soil nutrients on pasture because 60-95% of the nutrients consumed by grazing livestock pass through the digestive tract. Well distributed manure from grazing cattle contributes to added pasture growth.

• Temporary water systems utilizing plastic pipe laid over the soil surface and movable tanks work well and allow flexibility in keeping stock from congregating in loafing areas. Portable water systems are a powerful tool for managing manure cycling.

• Paddocks should contain a watering tank and also be laid out as near to square as possible to help facilitate in a more uniform manure distribution pattern.

• Shade and watering locations are sites of P and K accumulation in pastures because cattle tend to camp, loaf, defecate and urinate in these areas. While the nutrient gradient around shade areas does not seem to extend as far as around watering sites, the nutrient level is often higher than around watering sites.

• Grazing system features such as the number of paddocks, rotation frequency, stock density and water accessibility influences the distribution pattern of nutrients from grazing cattle manure.

• Distance traveled to water affects manure distribution. In larger paddocks greater grazing pressure occurs near the water source. This results in a significant manure gradient toward the water source as compared to manure distribution in smaller paddocks.

• Cattle in paddocks should have ready access to water, preferably within 700'-900' of the water source. Avoid laneways to prevent a nutrient loss of 15 - 20% due to cattle loafing and excreting in the lanes instead of in the paddocks.

• The impact of dung pats on pasture growth is longer term than urine due to slower dung decomposition and secondly the nutrient type and content of dung is phosphorus which is very stable and provides a longer effect on the soil and plant growth. Urine is the primary excretory path for potassium and soluble nitrogen which are relatively unstable, resulting in a short term effect.

• Dung pats are uniformly spread in pastures through increasing stocking density and decreasing grazing time. As the dung pats are spread more uniformly in the pasture, the rate of breakdown increases and nutrients become available sooner to plants.

• Grazing systems that supply water in every pasture and have the flexibility of water site placement require infrequent fertilization. Soil tests can be taken on a 3 to 4 year frequency to monitor nutrient status and plan fertilization strategies.

Research Papers

Grazing Management Affects Manure Distribution of Grazing Cattle

Grazing Management Affects Soil Phosphorus and Potassium Levels

Pasture type and fertilization effects on soil chemical properties and nutrient distrubution - available in PDF format only