Description of a sample of liquid dairy manures and relationships between analytical variables

摘要: A sample of 93 liquid dairy manures from Lombardy in northern Italy was analysed to determine manure composition, and regression equations for the prediction composition were developed. The had a mean (and standard deviation) dry matter content 95 (32) g kg−1, with total Kjeldahl nitrogen, ammonium carbon, phosphorus potassium concentrations 3.75 (1.00), 1.48 (0.45), 37 (13), 0.65 (0.24) 2.62 (0.77) g kg−1 [raw manure], respectively. It concluded that high variability is not compatible use tabulated average values nutrient management plans, requires traditional or simplified analyses reduce fertiliser input agro-ecosystems preserve crop yield. Linear regressions used estimate organic electrical conductivity. Because conductivity only measured on less than 103 g kg−1, based developed reduced sub-set 38 samples. Electrical an acceptable predictor coefficient determination (R2) 0.76. Carbon well predicted R2 0.98, while nitrogen estimated using both (R2=0.69 0.91, respectively). Unreliable predictions are obtained potassium. basic data required low-cost estimates useful improve effectiveness plans.