海南农田养分平衡状况及环境风险评价  

Nutrient balance in farmlands and the resulting environmental risk in Hainan Province

作　　者：洪秀杨 钟于秀 李伟芳 刘烁然 巨晓棠 阮云泽[1,2] 李婷玉 HONG Xiu-yang;ZHONG Yu-xiu;LI Wei-fang;LIU Shuo-ran;JU Xiao-tang;RUAN Yun-ze;LI Ting-yu(Sanya Nanfan Research Institute of Hainan University,Sanya,Hainan 572000,China;College of Tropical Crops,Hainan University,Haikou,Hainan 570208,China)

机构地区：[1]海南大学三亚南繁研究院,海南三亚572000 [2]海南大学热带作物学院,海南海口570208

出　　处：《植物营养与肥料学报》2022年第11期2070-2081,共12页Journal of Plant Nutrition and Fertilizers

基　　金：海南省院士创新平台科研专项(YSPTZX202019);海南省院士创新平台科研专项(SQ2020PTZ0004);海南省重大科技计划(ZDKJ2021008);海南省市厅级项目“农减项目-2021-1(2)”。

摘　　要：【目的】海南是我国区域经济作物种植面积占比最高的省。以海南主要农作物为对象,研究海南农田养分投入强度和作物养分平衡状况,从活性氮损失、温室气体排放和水体富营养化等方面评价施肥引起的环境风险。【方法】根据《海南统计年鉴》中的农作物种植结构,将海南省农作物分为粮食、蔬菜、水果和其他经济作物4类。采用随机抽样方法进行大样本农户问卷调研,共获取1199个有效样本。通过统计分析定量了海南岛主要农作物和各市县养分投入强度,化肥、有机肥施用结构,计算海南岛典型农作物体系水稻–辣椒轮作、香蕉和菠萝的氮磷养分平衡;采用相应环境模型,定量评价由于施肥带来的活性氮损失、温室气体排放以及富营养化效应等环境影响。【结果】目前海南主要作物化肥N、P_(2)O_(5)、K_(2)O养分的平均投入分别为261、206、225kg/hm^(2),分别高出全国平均水平10%、101%、148%,其中蔬菜磷和钾养分投入量分别高出全国平均水平164%和138%。全海南省各市县相比,沿海市县化肥养分施用强度高于中部市县,以昌江、海口的氮磷钾养分投入量大,高于投入最低的白沙、琼中等市县1.0~2.2倍。单质化肥以尿素、过磷酸钙和氯化钾为主,复合肥主要为N–P_(2)O_(5)–K_(2)O 15–15–15型。有机肥占总养分投入比例较低,粮食、蔬菜和水果的有机氮投入量分别为粮食、蔬菜和水果类作物总氮投入量的4%、20%和12%,低于全国平均水平。水稻–辣椒轮作、香蕉、菠萝种植体系的氮素单季盈余分别为N 520、675和668 kg/hm^(2),磷素单季盈余分别为P 217、277和228 kg/hm^(2),香蕉和菠萝种植体系氮素盈余是环境安全阈值的8倍以上。3个作物体系中,菠萝生产的单位面积活性氮损失、单位面积温室气体排放和富营养化效应最高,分别达到N 201 kg/hm^(2)、CO_(2)-eq 13112 kg/hm^(2)和PO_(4)-eq 121 kg/hm^(2【Objectives】Cash crop production accounts for a large proportion of agriculture in Hainan Province,China.Here,we compared the three typical crop production systems in Hainan,focusing on nutrient input rate and balance and the potential for environmental risks.【Methods】According to the Hainan Statistical Yearbook,the crops in Hainan Province are categorized into grains,vegetables,fruits,and other cash crops.Farmers were randomly surveyed,and 1199 effective samples were obtained.We investigated farmlands’nutrient source,input rate,and annual nutrient surplus.Further,we quantitatively evaluated environmental risks using reactive nitrogen loss,greenhouse gas emission,and eutrophication effect.【Results】The average chemical N,P_(2)O_(5),K_(2)O application rates in Hainan were 261,206,and 225 kg/hm^(2),which were 10%,101%,and 148%higher than the national average levels,and the excessive P and K application was particularly prominent in vegetables,reaching 164%and 138%higher than the national levels.Across the whole region of Hainan,coastal cities/counties had higher nutrient intensity than the central part,e.g.the nutrient input densities in Changjiang and Haikou were 1.0–2.2 times higher than those in Baisha and Qiongzhong.The most applied chemical fertilizers were urea,superphosphate,potassium chloride,and compound fertilizer in the N-P_(2)O_(5)-K_(2)O of 15-15-15.Organic fertilizers were used in low proportion,accounting for 4%,20%,and 12%of the total N input in grains,vegetables,and fruits,respectively,which are lower than the national average organic proportion.The annual N surplus in rice-pepper rotation,banana,and pineapple plantations were 520,675,and 667 kg/hm^(2),respectively.Similarly,the annual P surplus were 217,277,and 228 kg/hm^(2),respectively.The current N surplus in banana and pineapple production was over 8 times above the environmental safety threshold.Pineapple production exhibited the highest reactive nitrogen loss,global warming,and eutrophication potential.NO-leaching contributed

关 键 词：海南省 养分施用强度 养分平衡 活性氮 温室气体 水体富营养化 

分 类 号：X820.4[环境科学与工程—环境工程] X71[农业科学—土壤学] S158[农业科学—农业基础科学] X52