Maize Production And Utilizing In The Ecotone Between Agriculture And Animal Husbandry In Northeast China And Agricultural Ecosystem Optimization Model

Maize is the main crop in the ecotone between agriculture and animal husbandry in the northeast China. The thesis studied the maize intensively and systematically. The dynamics of maize biomass, chemical constituents in stalk, leaf and kernel of the maize, and the shearing force of the stalk as well as the color of the stalk were studied. Three kinds of harvesting methods have also been investigated. The first harvesting method is harvesting the stalk with ears early. The second method is that harvest the ears and stalk were kept on growing for 5 days. The third is cutting the top of the stalk. The effects of these methods on the production and nutritional value of the kernel and stalk have been studied. The effect of intercropping of maize with alfalfa in the ecotone between agriculture and animal husbandry in the northeast China was also analysed. The agricultural ecosystem has been optimized. And the conclusions were drawn from the above work.The maize stalk's shearing force increased with the delaying of harvesting date. Shearing force is influenced by cell wall chemical constituents. There is a positive relationship between shearing force and acid detergent lignin(ADL), hemicellulose and cellulose content. The color of the stalk went from green to yellow with the developing of the maize, and the chemical constituents in the stalk were changed at the same time.Relation between crude protein and color of the stalk has been studied. Itwas found that the crude protein content decreased with the changing of the color. The crude protein content is an important indicator of the stalk nutritional value. So the stalk nutritional value decreased with the color getting lighter. The temporal and spatial of dynamics of biomass of maize leaf and stalk have been studied. The biomass of maize leaf and stalk reached the peak and then decreased during the period of growth. The temporal and spatial of dynamics of chemical constituents of maize leaf, stalk and kernel have been studied. The feeding nutritional value of the leaf and stalk decreased with the developing of the maize. The optimum harvesting date of maize in the west of Jilin province was determined according to the above work. The optimum harvesting date of maize is about 10 September according to the biomass of stalk and leaf. The optimum harvesting date of maize is about 20 September according to nutrition value of the stalk and leaf. Compared with traditional harvesting date, 31.27Kg more crude protein can be obtained if maize is harvested on 20 Sept.. The crude protein provides a sheep with 312 days protein requirement. If the maize is harvested on 20 September, 1.695GJ more energy can be obtained than when it is harvested on the traditional date. The energy provides a sheep with 150 days energy requirement.The thesis has also studied the effects of harvesting methods on production and chemical constituents of the kernel and stalk. It was found that the methods of harvesting stalk with ears early and cutting the top of the stalk reduced the production of the kernel but improved the quality and quantity of the stalk. The methods of harvesting ears and stalk growing 5 days larger improved the crude protein content of the stalk. The harvesting methods all can be put in practice in the area according to factual requirement.The effect of intercropping of maize with alfalfa was analysed. The intercropping can not only enhance the utility efficiency of the ground but also promote the integration of farming with animal husbandry. Theintercropping increased forage grass and mitigate the scarcity of forage. It also mitigate the scarcity of ground. The method is reasonable in the ecotone between agriculture and animal husbandry.The agricultural ecosystem in the investigation area has been optimized. The outcome showed that maize's dominant position can not be changed. The sowing area of soybean should be increased to optimize the agricultural ecosystem. The quantity of chook should be reduced, however the quantity of cattle should be incre...