Abstract:

This paper examined the straw yield of crops and their potential as nutrient resources in Guangdong Province, aiming to provide a scientific basis for rational utilization of straw nutrient resources, reduction of chemical fertilizer imports, and the development of green agriculture. Rice, maize, potato, sugarcane, peanut, and soybean, which are the main crops in Guangdong Province, were selected as research objects. Based on agricultural statistics and published literature, the straw yield of crops, straw nutrient resources, and their regional distribution in Guangdong Province in 2019 were estimated. According to the recommended nutrient consumption of different crops, the nutrient requirements of different regions were calculated, and the potential of straw nutrient resources to replace chemical fertilizer was analyzed. The results showed that the main crop straw resources in Guangdong Province were 1951.00×10⁴ t, of which the resources of straw in western Guangdong were the largest, followed by Northern Guangdong, while the Pearl River Delta had the least. The total amount of nitrogen (N), phosphorus (P₂O₅) and potassium (K₂O) nutrient resources of straw in the province reached 19.26×10⁴, 4.51×10⁴, and 33.51×10⁴ t, respectively. The largest straw nutrient resource came from rice, accounting for 63% of the total nutrient resources, followed by sugarcane straw (18%) and peanut (10%). The largest straw nutrient resource were in Zhanjiang City, accounting for 25% of the province's total nutrient resources, of which sugarcane and rice straw contributed the most. The second and third largest, mainly came from rice straw, were in Maoming City and Zhaoqing City, which accounted for 11% and 8%, respectively. In 2019, the main crops sown area in Guangdong was 265.91×10⁴ hm². Theoretically, the nutrient requirements of this area were as follows: 46.18×10⁴ t N, 15.78×10⁴ t P₂O₅, 40.41×10⁴ t K₂O. The potential of straw nutrient resources to replace chemical fertilizer was N 22%, P₂O₅ 19% and K₂O 70%. The potential of straw to replace chemical fertilizers varied in different cropping systems, among which, rice and sugarcane had the greatest potential to replace potassium fertilizer with straw; green beans had the greatest potential to replace nitrogen fertilizer with straw; and potato straw had the lowest potential to replace chemical fertilizers. In addition, the potential of straw to replace chemical fertilizers varied among different cities. Zhanjiang and Guangzhou had the highest potential to replace nitrogen fertilizer with straw (30% and 29%); Zhuhai City and Meizhou City had the highest potential to replace phosphate fertilizer with straw (26% and 24%); and Meizhou had the highest potential to replace potassium fertilizer with straw (78%).

Key words: straw yield, straw nutrient resources, chemical fertilizers substitution, regional distribution, Guangdong Province

摘要：

合理利用秸秆养分资源可替代部分化肥使用,是种植业减肥增效并促进农业绿色发展的重要途径之一,探明广东省主要农作物秸秆养分资源量及其替代化肥潜力,对于全省化肥减施增效、农业绿色生产具有重要意义。该研究以广东省主要农作物水稻（Oryza sativa L.）、玉米（Zea mays L.）、薯类（Dioscorea esculenta (Lour.) Burkill）、甘蔗（Saccharum officinarum L.）、花生（Arachis hypogaea Linn.）和大豆（Glycine max (Linn.) Merr.）为研究对象,通过查阅广东省统计数据和公开发表的文献资料,对2019年广东省主要农作物秸秆数量、养分资源量及区域分布情况进行估算,并根据不同作物推荐养分用量计算各地区的养分需求量,分析秸秆养分资源替代化肥的潜力。结果表明,2019年广东省主要农作物秸秆资源量为1951.00 ×10⁴ t,其中粤西秸秆资源量最大,其次是粤北,珠三角地区最少。全省秸秆的氮（N）、磷（P₂O₅）、钾（K₂O）养分资源总量分别达到19.26×10⁴、4.51×10⁴、33.51×10⁴ t,其中水稻的秸秆养分资源量最大,占全省农作物秸秆养分资源总量的63%;其次是甘蔗秸秆养分资源,占18%;第三大秸秆养分资源是花生,占10%。湛江市的秸秆养分资源最大,占全省秸秆养分资源总量的25%,其中甘蔗和水稻秸秆的贡献率最大;其次为茂名市和肇庆市,占11%和8%,以水稻秸秆养分资源为主。广东省2019年主要农作物播种面积为265.91×10⁴ hm²,理论上养分需求量为46.18×10⁴ t N、15.78×10⁴ t P₂O₅、40.41×10⁴ t K₂O,秸秆养分资源替代化肥的潜力为N 22%、P₂O₅ 19%、K₂O 70%。不同种植制度下秸秆替代化肥的潜力不同,其中,水稻和甘蔗秸秆替代钾肥潜力最大,大豆秸秆替代氮肥潜力最大,而薯类秸秆替代化肥潜力最低。不同地区的秸秆养分资源替代化肥潜力不同,其中湛江市和广州市秸秆替代氮肥的潜力最高,分别达30%和29%;珠海市和梅州市秸秆替代磷肥的潜力较高,分别达26%和24%;梅州市秸秆替代钾肥的潜力最高,达78%以上。

关键词: 秸秆产量, 秸秆养分资源, 化肥替代, 区域分布, 广东省