Abstract:

The natural characteristics of grassland resources determine the limited livestock carrying capacity of pasture， which is suitable for grazing only at specific time windows in a year and cannot bear long-term and continuous grazing. The unreasonable grazing path planning will not only lead to the mismatch between livestock feeding time and pasture growth cycle， but also lead to a series of negative problems such as overload， underload and degradation of pasture. In this paper， based on the consideration of grass-livestock balance， the grazing time penalty function is proposed， a linear time window and exponential time window grazing path planning model is constructed， and an improved genetic algorithm is designed to solve the model. Finally， the model is validated with an example of a herding household in Haiyan County， Qinghai Province. The results show that the algorithm with exponential time window can find the optimal solution faster. Furthermore， considering the three cost leads to lower total grazing path costs than focusing on a single cost. The improved genetic algorithm shortens the solution time and improves the stability of the solution. The path planning model with time windows constructed in this paper fully considers the natural attributes of pasture， optimizes the grazing path of herders， and improves the scientific use of pasture resources by herders.

Key words: grass-livestock balance, livestock carrying capacity, time window, grazing path planning