| Vegetative agriculture is a kind of productive system, which concentrates mainly on the production of vegetative organs such as stems and leaves of plants including herbages, green fodder, vegetations, flowers, teas, tobaccos, as well as rhizome and fibre crops. The principal difference between the traditional agriculture and vegetative agriculture is that the former focuses on the productivity of the seed in the whole growing period and the latter focuses on the productivity of available nutrients at the different growing stages of plants. Therefore, the plants need a whole growing period to produce more seeds in the productive system of traditional agriculture, but the plants have to be harvested at the certain growing stages to gain more economic production in the productive system of vegetative agriculture.Types of vegetative agriculture are highly related to the sunshine, temperature, precipitation and length of growing season. In the regions, where insufficient sunshine, low temperature, deficient precipitation and short growing season limit the high and stable production of seeds, the vegetative agriculture can be well developed.Among types of vegetative agriculture in China, some researchers have paid their attentions to efficient utilization of winter fallow lands in Southern China. Document on mechanism and efficiency of developing vegetative agriculture in alpine regions of Qinghai-Tibetan Plateau, Karst regions of Yungui Plateau and arid, semi-arid farming regions of Northern China are still scarce. On this basis, studies of vegetative agriculture production were conducted from the year of 2000 to the year of 2001 at Jinqianghe Alpine Grassland Research Station of Gansu Agricultural University (GAU), Tianzhu County (altitude 2964m), Huazangsi Town of Tianzhu County (altitude 2390m) and Lanzhou Herbage Station of GAU (altitude 1517m) by comparing three kinds of plants, i.e., annual ryegrass (typical forage crop), oat (dual crop) and spring wheat (the grain crop). The results indicate that:1. Due to low temperature, annual ryegrass stopped growth at pre-mature stages of the plant in Jinqianghe. And the fully mature seeds of annual ryegrass couldn't be harvested in Huazangsi either due to low temperature at the late growing stages. Although annual ryegrass produced some seeds in Lanzhou, the production was fairly low. Leaf area index (LAI) of annual ryegrass was the highest among all these crops, and increased with the rising altitude, LAI of oat took the second place, followed by spring wheat. Although oat and spring wheat got mature in three places, the productions were relatively low.2. Annual ryegrass gave the highest whole plant biomass (WPB), net primary productivity (NPP), net nutrient productivity (NNP) and net energy productivity (NEP) in three places under four harvests of different growing stages, followed by oat and spring wheat. The average WPB of ryegrass in three places at four harvesting stages was 61.4% and 212.8% higher than that of oat and spring wheat respectively. The fact that TP of ryegrass was the highest at blooming stages and the lowest at seeding stages shows the characteristics of vegetative crops. On the contrary, the fact that TP of oat and ryegrass was the highest at seeding stages of the plant and the lowest at jointing stages shows the characteristics of seed crops.3. Average biomass, NPP, NNP, NEP, crude protein (CP) content, crude fat (CF) content and dry matter (DM) degradability of aboveground vegetative parts of these three crops at four harvesting stages followed the same pattern with TB, i.e. ryegrass is the highest, oat is the second and spring wheat is the third. Generally, Average biomass, NPP, NNP, NEP, CP, CF content and DM degradability of these three crops harvested several times at growth stage was higher than that harvested at the seeding stage.4. The proportion of average biomass, NPP, NNP and NEP of aboveground vegetative parts to WPB of these three crops increased with the rising altitude, i.e. vegetative organs increased and repr...
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