黄土高原玉米坡耕地C因子的估算研究  

Study on the Estimation of the C-factor in Maize Sloping Cultivated Land on the Loess Plateau

作　　者：余倩 姚冲 付世琳 吴发启 YU Qian;YAO Chong;FU Shilin;WU Faqi(State Key Laborary of Soil Erosion and Dryland Farming on the Loess Plateau,Yangling,Shaanxi 712100;Institute of Soil and Water Conservation,Northwest A&F University,Yangling,Shaanxi 712100;College of Resources and Environment,Northwest A&F University,Yangling,Shaanxi 712100)

机构地区：[1]黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100 [2]西北农林科技大学水土保持研究所,陕西杨凌712100 [3]西北农林科技大学资源环境学院,陕西杨凌712100

出　　处：《水土保持学报》2022年第6期49-54,共6页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(41977065);国家重点实验室开放基金项目(k3050219171)。

摘　　要：C因子作为土壤侵蚀预报模型中人为可控制的一个重要的因子,对减少土壤侵蚀和控制水土流失有很大的影响。因此以黄土高原坡耕地典型作物玉米为研究对象,通过进行人工降雨模拟试验,研究了玉米5个不同生育期近地表状况的变化特征,根据玉米不同生育期产沙量计算C值。结果表明,植被覆盖度、株高和结皮厚度均随着玉米生育期的延长而逐渐增加,地表粗糙度随着生育期延长呈现先减小后增加的趋势。产沙量随着玉米的生长逐渐减小,减沙效益随着玉米生育期的延长不断增加。在前人以植被覆盖度计算C值模型的基础上,以植被覆盖度作为关键因子,将株高、土壤结皮、地表粗糙度作为调节因子建立当地C值模型,得到较好的玉米坡耕地的C值模型(模型R^(2)=0.94,RMSE=0.017,MAE=0.014,NSE=0.992)。研究结果根据近地表状况变化特征建立C值计算公式,提高了C值估算的准确性和其在黄土高原的适用性,为提高黄土高原土壤侵蚀预报模型精度提供科学依据。The C factor is an important artificially controllable factor of soil erosion prediction model. It plays a vital role in reducing soil erosion and controlling water and soil loss. In this paper, the maize, a typical crop on sloping farmland of the Loess Plateau, was studied using an artificial rainfall simulation experiment. Besides, five change features of maize on near-surface conditions in different growth periods were analyzed and the C value was calculated according to the sediment yield of maize in different growth periods. The results showed that vegetation coverage, plant height and crusted thickness increased gradually with the prolongation of maize growth period and that the surface roughness decreased first and then increased with the prolongation of maize growth period. Besides, the sediment yield decreased gradually with the continuous growth of maize and sediment reduction benefit increased with the extension of maize growth period. Based on the previous C-value model calculated by vegetation coverage, the vegetation coverage was taken as the key factor and the plant height, soil crust and surface roughness as the adjusting factors to build a local C-value model. On the basis of that, a better C-value model for maize slope farmland(model R^(2)=0.94, RMSE=0.017, MAE=0.014, NSE=0.992) was obtained. Based on the research results, a C-value calculation formula was established according to change characteristics of near-surface conditions. This helped improve the accuracy of C-value estimation and its applicability to the Loess Plateau, which could provide a scientific basis for improving the accuracy of soil erosion prediction model on the Loess Plateau.

关 键 词：C值 土壤侵蚀 玉米 产沙量 

分 类 号：S157.1[农业科学—土壤学]