Response Of Grassland Characteristics And Horqin Cattle's Pasturing Behavior To Grazing Regimes In Horqin Region

Effects of rotational and continuous grazing on plant population, community, soil characteristics and grazing behavior of Horqin cattle among fixed sandy land, semi-fixed sand land and shifting sandy land were comprehensively investigated by field observation, sampling, laboratory experiment and statistical analysis during 2005-2007. The main results were as follows:1. Horqin sand was divided into 3 types of sand, fixed sandy land, semi-fixed sandy land and shifting sandy land, different types of sand had different plant community and characteristics. There weren't significant differences on shrub height, coverage and density between two grazing systems. Rotational grazing system enhanced height, coverage and density of community and Agriophyllum squarrosum in shifting sandy land. There weren't significant differences in height, coverage, density of Pennisetum centrasiaticum between two grazing systems in semi-fixed sandy land. Rotational grazing system enhanced coverage, density of Lespedeza davurica. There weren't significant differences in height of Lespedeza davurica between two grazing systems, however the rotational grazing system improved the density and coverage of while had no effect on height.2. Rotational grazing system was beneficial to maintain or improve plantαdiversity index in different months of treatment with different grazing conditions in Horqin sand, while the highest similarity index of community appeared in rotational grazing and control conditions.3. The important value of Artemisia halodendron in three different treatments was ranked in the first place in the shrub layer of the main plant populations, which of Agriophyllum squarrosum, Corispermum macrocarpum and Setaria viridis were higher in shifting sand land. And of Corispermum macrocarpum, Setaria viridis, Pennisetum centrasiaticum and Lespedeza davurica were all at front in different treatment. Cleistogenes squarrosa had absolute predominance in control condition, followed by Lespedeza davurica and Pennisetum centrasiaticum in herbaceous population of fixed sandy land, Pennisetum centrasiaticum had a dominance status but that of Lespedeza davuricaincreased gradually over time while Cleistogenes squarrosa in Sep. and Oct. appeared Outstanding. Rotational grazing conditions were an intermediate transitional between control and continuous grazing.4. Rotational grazing system enhanced the standing crops of plant community in shifting sand land and fixed sand land, especially enhanced the standing crops of Caragana microphyll, Agriophyllum squarrosum in shifting sand land, that of Cleistogenes squarrosa, Lespedeza davurica, Phragmites australis in fixed sand land. Rotational grazing system enhanced the standing crops of annual and perennial plants in semi-fixed sand land. There has no linear relationship between bush layer plant population and reducing sugar where there had a remarkable linear relationship between the herb layer plant populations and reducing sugar content.5. The number of plant seedlings in shrub layer was rotational grazing > continuous grazing > control plot, which in herb layer was control plot > rotational grazing > continuous grazing, the number of Artemisia halodendron in shrub layer and Lespedeza davurica in herb layer were largest but Ulmus pumila and Carex duriuscula and Cleistogenes squarrosa had a contrary result. Seedlings of different species appear at different time in the growing season. Shrub species seedlings mainly appeared from July to September, while herbaceous plants mainly in the June to July.6. Soil nutrient content of Horqin sand was not high, which also changed with different types of landscape patches. The contents of total nitrogen and potassium in fixed sand land were higher than that in semi-fixed sand, and of which in semi-fixed sandy soil were higher than that in drifting sand land. The contents of alkali nitrogen and in fixed sand were higher than that in semi-fixed sand, and of which in semi-fixed sand were lower than that in drifting sand land. The contents of total nitrogen and phosphorus, total nitrogen and available phosphorus and total phosphorus and available phosphorus were significantly correlative. Soil moisture and organic matter content in fixed sand was higher than that in semi-fixed sand, and of which in semi-fixed sand was higher than that in drifting sand land.7. The selective intake of Horqin cattle was high .Not only reflected in the types of forage, but also in grass growing season, which mainly selected the part that easy to digest, the proportion of Setaria viridis was higher than 45% both in two grazing systems. The average plant population stubble height had different performance in different months between different grazing systems, the performance under rotational grazing conditions was October >July >August >September; while in continuous grazing conditions showed October >September >August >July. Horqin cattle has mainly intake and activity in the semi-fixed sand. There had different feeding rate feeding habits and eliminative behavior in different grazing systems, the feeding line and feeding time is short in rotational grazing condition which had a high feed rate and feed intake, longer rumination, resting and standing time, less defecation times.