| Summary: | 碩士 === 國立宜蘭大學 === 園藝學系碩士班 === 99 === Abstract
The hottest public issue today is saving energy and carbon reduction, but actual solid remedy measure or technology applied in local circumstance or agriculture industry is very limited. For instance, how to creat and maintain low carbon and low toxin environment? Using animal to manage landscape is a long history regime in western countries, but to use them as a pest controlling agent in the farmland as organic farming tool and/or extending such application in terms of forms, occasions, efficacy and season…etc. has not been well studied. This thesis is aimed to study the feasibility and efficacy by using poultry as landscape/farmland management agent holistically. It is to explore the the above technology systematically from view point of environment, animal welfare, economy and ecology. It is hoped that the results is of value to improve aesthetic landscape, environmental friendly production and quality life etc. those related to rural infrastructure/development in Taiwan.
In environmental aspect, poultry grazing was assessed in various occasions, such as turfgrass, flowering meadow, flowering bulb production, native and commercial turf grass. Most of the tested fowls show high interests in grazing vegetation, therefore hight, density, colour, weed invasion, and quality of turf grass canopies were significantly affected to different degrees according to grazing poultry species/breeds. Either cage or open field bred, the growth quality or survival of the vegetation were decided by the tolerance of poultry’s pecking and trampling. On the other hand, vegetation/habitats preference of poultry were significantly distinguished. For instance, bared ground with shelter was preferred the most among short sward, long sward, bare ground, and bare ground with shelter particularly in rainy days. Short sward was the most favorite in the sunny days, on the other hand. Nevertheless, it was not the case for the wild species such as guinea fowls which wondered in short sward most of the time no matter what weather might be. Terrestrial bird show difference from water fowls which prefer open bare ground and grassland, large water fowls such as geese show greatest interest in long sward among all the observed fowl species. The long sward became short sward and short sward became even shorter or bare ground even it is not the most visited habitats over 3 months grazing. Both of the controlled counterparts of long and short sward became long sward.
It seems that the effects of grazing on the cropland were determined by the preference of plant species and tolerance of poultry tampling. The survived plants were the tallest and wooden species which might escape from the bird feet. Crop such as citrus, sugar cane, mango were superior to the taro and pine apple. Weeds such as Ludwigia octovalvis survived Pasplalum conjugatum, Eclipta prostratav and Alternanthera philoxeroidex Better trampling tolerance and less palatability of Zephyranthes candida and Z. ajax showed again in the flowering meadow experiment that they were the most successful crop plant survived fowl bills and feet in the composed flowering meadow community. To maintain flowering meadow which turfgrass and Zephyranthes coexist, grazing mode, duration of time and fowl density/number need to be studied further . Following 16 months of grazing all the turfgrass were killed and only Zephyranthes survived. To compared with regime of mechanical mowing, flower number and bulb yield of Zephyranthes during experiment and at the end of experiment, the landscape value and efficiency of crop production,regime of poultry grazing is superior. On the contrary of open cropland, grazing assessment of weeding in the potted Zephyranthes, only black pheasants and quails showed positive results that weeds were distinguished from Zephyranthes by the fowls. Poultry grazing may potentially partly or completely takes over mowing and weeding. Poultry grazing on Paspalum vaginatum and Zoysia matrella turfgrass, Z. matrella showed higher grazing carrying capacity, but the quality of turfgrass was P. vaginatum at the end of experiment. The result could be resulted from growth of the warm season grass deteriorated. Further more, the complex variable analysis showed no difference in grass species. Taking an example of the carrying capacity of poultry grazing in the Polish fowl, the value for the whole space is per bird/0.45m2×3days and the value for the turfgrass is per bird/360cm2×3 days. The Polish fowl and Japanese bantam are better than the Taiwan country chicken and the silky fowl in terms of the fowl breeds.The negative effects of fowl grazing are the possible reduction of grass coverage and weed introduction, but canopy height is definitely controlled. Weed/grass intake is beneficial for chicken and farmer income. Although not always consistanty, forage is similar to probiotic that is generally positive for fowl development and egg laying.
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