Researches On Resource Amount Of Agricultural Wastes And Strategies Of Its Utilisation In Zhengzhou City

There are lots of agricultural straw resources and livestock manure in Zhengzhou city every year. However, the total quantity of the agricultural solid wastes is not clear. If their total quantity is ascertained, the agricultural wastes will be utilised more effectively and reasonably under the government making feasible and comprehensive plans in Zhengzhou city. Therefore, the total quantity and the utilisation status and pathes of agricultural straw and livestock manure were studied in the paper. Firstly, based on a large number of relevant references at home and abroad, a series of parameters were dermined after the field investigation on some large planting areas and livestock and poultry farms and household was carried out, including ratio of grain to straw, livestock breeding period, livestock manure discharge per day,and the percentage composition of organic matter, N, P and K in crop stalks and livestock manures respectively. Secondly, on the basis of the parameters determined above the total resources quantity of agricultural crop stalks and livestock manure, at the meantime, and the resource quantities of organic matter and N and P and K of agricultural waste were calculated. Lastly, the feasibility of soil absorbing all the nutrient which the agricultural wastes can provide was discussed. The conclusions were reached as follows:There were abundant straw resources and different kinds of crops had different straw quantity and obvious distribution differences in Zhengzhou city. The straw quantity in 2009 was 1.85m tonnes in Zhengzhou city. Specifically, maize and wheat straw which were the two main straw resources in Zhengzhou city amounted at 0.89m tonnes and 0.87m tonnes, accounting for 44% and 43% respectively. Meanwhile there were substantial nutrients of the agricultural straw in 2009, exactly,1.36m tonnes organic matter and less than 7 kilotons nitrogen and 874 tonnes phosphorus and about 10kilotons potassium were found. Zhongmou county where the total agricultural nutrients quantity amounted at 328 kilotons, had the most quantity of agricultural nutrient in Zhengzhou city, accounting for 23.74%. In terms of the utilisation of straw, the four differrent utilisation methods—as fertilizer and feed and energy and material accounted for 61.78%,24.65%,3.17%and 5.58%, respectively.The discharge quantity of livestock manure in 2009 was 5.87m tonnes in Zhengzhou city. Specifically, cattles and pigs produced the two main liverstock manure in Zhengzhou city, accounting for 63.1% and 24.5% respectively. Different kinds of livestock had different straw quantity and obvious distribution differences. More precisely, the livestock manure quantity was 2.16m tonnes in Zhongmou county while the quantity it was 0.95m tonnes in Xingyang county. There were substantial nutrients of livestock manure in 2009, to be more exact,1.23 m tonnes organic matter and 28.9 kilo tons nitrogen and less than 8kilotons phosphorus and 0.17m tonnes potassium were discharged respectively. In terms of its utilisation, about 37.25% livestock and poultry farms produced methane from livestock manure while 33.87% farms, mainly cattle farm, produced organic fertilizer or inorganic and organic compound fertilizer.If the soil organic matter percentage composition is increased from 1.66% to 4.7% in 10years in Zhengzhou city, about 528.41kg organic matter per acre should be put into the soil every year. There were 2.59m tonnes organic matters in the agricultural waste in 2009 in Zhengzhou city, which means the soil could be send about 525.91kg per acre. In general, there was a balance between supply and demand of organic matter in Zhengzhou city. To be more precise, in Zhongmou and Xingyang and Xinzheng the supply was greater than the demand of organic matter while the results were reverse in Gongyi and Xinmi and Dengfeng. There was a nearly balance in the downtown of Zhengzhou city.There are 35627tonnes nitrogen,9757tonnes phosphorus and 16969tonnes potassium of agricultural straw and livestock manure in Zhengzhou city, and the total quantity account for50%,20% and 90% of the chemical fertilizer--nitrogen, phosphorus and potassium fertilizer, respectively.