关中地区耕地显性与隐性非粮化的时空变化及对粮食产量的影响

确保粮食安全是中国治国理政的头等大事，当前耕地非粮化对粮食生产产生严重影响。该研究以关中地区为例，研究耕地显性非粮化、隐性非粮化的时空变化及对粮食产量的影响。结果表明，关中地区耕地显性、隐性非粮化程度在加剧。2000—2010年、2010—2020年显性非粮化面积占2010年、2020年耕地面积的比例分别为5.19%、29.10%，2000年、2010年、2020年隐性非粮化面积占当年耕地总面积的比例为51.69%、55.07%、66.69%。耕地显性、隐性非粮化导致的粮食损失量呈增加趋势，且隐性非粮化导致的粮食损失量远大于显性非粮化。2000—2010年、2010—2020年，显性非粮化导致的粮食损失量占2010年、2020年粮食产量的平均值为0.10、0.74。2000年、2010年、2020年隐性非粮化导致的粮食损失量与当年粮食产量的比值的平均值分别为1.37、1.16、1.95。基于此，在当前缺少耕地隐性非粮化有效治理措施的情况下，亟需进行耕地隐性非粮化治理政策措施的研究与制定。耕地隐性非粮化的根本原因是粮食种植的收益低，应当加大种粮补贴力度，通过补贴弥补粮食种植收益低的短板，以提高农民的粮食生产积极性。

Effects of spatiotemporal variations in visible and invisible non-grain production cultivated land on grain yield in the Guanzhong Region of Shaanxi in China

Non-grain production of cultivated land has a serious impact on grain production and national food security. Taking as a research area, this study aims to clarify the temporal and spatial changes of visible non-grain production of cultivated land (VNGPCL), and invisible non-grain production of cultivated land (INGPCL). The land use, vegetation index, and socio-economic data were also collected in 2000, 2010, and 2020. A systematic investigation was then implemented to determine the effects of VNGPCL and INGPCL on the grain yield. The results show that the degree of VNGPCL was ever-intensifying, where the areas were 131276.93 and 744755.60 hm² in 2000-2010 and 2010-2020, respectively. There was a 5.19% proportion of VNGPCL area in 2000-2010 to total cultivated land area in 2010. By contrast, there was a 29.10% proportion of VNGPCL area in 2010-2020 to total cultivated land area in 2020. The area of VNGPCL from 2010 to 2020 was 5.61 times that of from 2000 to 2010. The VNGPCL was transformed mainly into grass land, urban and rural construction land, forest and garden land. There was also the ever-increasing area and proportion of INGPCL each year. The areas of INGPCL were 1306663.34, 1409341.58, 1608487.67 hm² in 2000, 2010, and 2020, respectively. The proportions of INGPCL area to the total cultivated land area in 2000, 2010 and 2020 were 51.69%, 55.07% and 66.69%, respectively. There was a significant spatial auto-correlation in the VNGPCL and INGPCL from 2000 to 2020, indicating the increasing spatial agglomeration. An increasing trend was found in the grain lost caused by VNGPCL and the proportion to grain yield. The average amount of grain lost caused by VNGPCL accounted for 0.10 and 0.74 of the grain yield in 2010, and 2020, respectively. The grain lost caused by INGPCL was greater than that by VNGPCL in 2000, 2010, and 2020. An overall increasing trend was found in the proportion of grain lost caused by INGPCL to grain yield from 2000 to 2020. The average grain lost caused by INGPCL to the grain output was 1.37, 1.16 and 1.95 in 2000, 2010, and 2020, respectively. The grain lost caused by INGPCL was much greater than that by VNGPCL. Therefore, the INGPCL can be attributed to low grain cultivation. It is an important way to reduce the INGPCL for higher grain yield and grain security. Effective measures are also urgent to manage and formulate the INGPCL for better grain production.