Agro-ecological assessment of manure from different farm animals by content of biogenic elements

Abstract. The aim of the present study was to investigate and to make agro-ecological assessment of fresh (excreted up to 24 h) and stored (for 6 months)manure from different farm animals (dairy cows, pigs, laying hens and turkeys) by biogenic elements content (N, P, K) for a period of one year. Samples of freshand stored manure were collected and analyzed monthly for total N, total P and total K content. It was found that: a) biogenic elements in fresh and storedmanure decreased in the following gradation by average values for the studies period: turkeys – total N (13.9 - 9.16 g/kg DM), total P (9.94 - 8.67 g/kg DM) andtotal K (5.02 - 3.74 g/kg DM); laying hens – total N (13.6-9.95 g/kg DM), total P (9.27- 7.94 g/kg DM) and total K (5.56 - 4.60 g/kg DM); pigs – total N (8.30 -6.77g/kg DM), total P (6.08-4.65 g/kg DM) and total K (3.56 - 1.61 g/kg DM); dairy cows – total N (5.62 -4.76 g/kg DM), total P (1.72 - 1.48 g/kg DM) and total K (2.99 -1.72 g/kg DM); b) the change in nutrients content of different types of manures by seasons both in fresh and in stored manure are divergent; c) coefficients ofvariation values determined surveyed manures by content of nutrients from minor to significant variable (C = 9.30-37.5%); d) during the storage of the tested vmanures nutrient losses are the greatest for potassium (17.3-54.8%), followed by nitrogen (15.3-34.1%) and phosphorus (12.8-23.5%); e) the average lossesof biogenic elements in manure by kind of animal species are in varying degrees: dairy cows (total N 15.3%, total P 14.0%, total K 42.5%); pigs (total N 18.4%,total P 23.5%, total K 54.8%); laying hens (total N 26.8%, total P 14.3%, total K 17.3%) and turkeys (total N 34.1%, total P 12.8%, total K 25.5%); f) the ratiobetween nutrients (N:P:K), both in fresh and in stored manure from different animal species vary in relatively wide limits both by seasons(12.6%N:18.1%P:56.3%K – 41.5%N:16.0%P:39.7%K) and by average of the studied period (15.3%N:14.0%P:42.5%K – 34.1%N:12.8%P:25.5%K).