Estimation Of The Nutrient Contents In Poultry Manure

Aim at the current situation of serious environmental pollution caused by intensive husbandry, the author discussed the necessity and possibility of realizing organic agriculture in China, and elucidated that disposal of livestock manure to agricultural land is the most economical and environmental sound solution for organic agriculture. It was required to estimate the nutrient contents in animal manure for utilizing animal manure as a resource. There are two methods for estimating the nutrient contents in animal manure. The first one is rapid tests based on the testing technology of physical-mechanical characteristics, and the second one is mathematical model. This paper reviewed the two methods separately and discussed the further study at the same time. Quick tests could estimate the nutrient contents rapidly by constructing the relationships between the physical-mechanical characteristics and total nitrogen, phosphorus~ potassium and ammonium contents in animal manure, and then testing these physical-mechanical characteristics, such as specific gravity, conductivity and dry matter, etc. According to some independences, such as dietary intake, liveweight, etc, the nutrient contents in animal manure could be estimated rapidly and accurately through the calculation of the mathematical model. The two methods, which are more convenient, rapid and low-priced, compared with the conventional lab analysis, will save a great lot of human and material resources when put them into practice, and have important theoretical and applied values for promoting to use animal manure scientifically and fulfilling the sustainable agriculture. Studied the mathematical model method, which is based on the data of poultry and the formulation of their dietary intake. By theoretical analyzing the influential factors of the volume and nutrient contents of animal manure, the independences of the model were selected and they were animal type, age, liveweight, feed input, dry matter intake, N, P and K intake, dry matter output and slurry output. Broiler -Iv - experiment was carried out from which a large number of data were obtained. By regression analysis, the most important factors for estimating the volume and N, P, K contents of broiler manure were attained. A series of empirical model were developed. It was tested that these models were reasonably reliable. Using animal age as a predictive independence was presented for the first time. Simple equations of using broiler age as an independence were developed separately, and the regression relationships were highly significant. Combining age and other factors instead of liveweight attained multiple equations, which are more reliable and useful. Selected the most reliable, economical, simple and useful models. The results of the estimation were identical with the experiment results on the whole. Studied the rapid tests method, which is based on the testing technology of physical-mechanical characteristics. 20 broiler slurry samples were collected for the purpose of studying the relationships between specific gravity, conductivity and the nutrients in animal manure. According to the results of regression analysis~ specific gravity can estimate the P contents in animal manure, and conductivity can estimate the ~ and K contents precisely. Besides, the influence of dilution to the conductivity of the solutions was tested. The...