天津市中低产田时空分布与限制因素研究

为了解天津市中低产田面积变化情况及中低产田空间分布情况，为天津市中低产田改良及粮食增产提供基础依据，以天津市统计年鉴及相关区县统计年鉴数据为依据，拟定了高、中、低产田划分标准，分析了天津市6个主要农业区县（蓟县、武清区、宝坻区、宁河县、静海县和滨海新区大港）1980—2010年30年间中低产田面积变化情况。结果表明：经过30年的不懈努力，天津市粮食平均产量由1980年的2445 kg/hm²提高到2010年的5130 kg/hm²，增加了109.82%。天津市的中低产田面积由1980年的291250.13 hm²，下降至2010年的76489.87 hm²，下降了74%。2010年天津市中低产田面积占全市耕地总面积的19%，其中静海县、蓟县、滨海新区大港、武清区、宝坻区、宁河县中低产田分别占全市中低产田总面积的43.12%、18.59%、17.23%、14.01%、7.05%和0。2010年天津市中低产田粮食增产限制因素分析表明，土壤养分含量低、干旱缺水和土壤盐渍化是主要限制因子。建议继续加大政府资金投入、强化水利基础设施建设、进一步提高土壤肥力、综合改良盐碱地、优化耕作制度种植耐旱耐盐作物品种等工程与技术措施，持续改良中低产田。

Spatial-Temporal Distribution Characteristics and Limiting Factors of Medium-low Yield Farmland in Tianjin

This paper aimed to understand the area change and distribution of medium-low yield farmland, and offered basis to the improvement of medium-low cropland and its increase of grain production in Tianjin. Based on the statistical date of Tianjin and its relevant counties and districts, the yield standard was set up to classify high-yield, medium-yield and low-yield cropland in Tianjin. The author analyzed area change of medium-low yield cropland in six agricultural counties and districts (including Jixian County, Wuqing District, Baodi District, Ninghe County, Jinghai County and Dagang of Binghai New Area) from 1980 to 2010. The results showed that the average yield of grain rose from 2445 kg/hm2 in 1980 to 5130 kg/hm2 in 2010, increasing 109.82%. The area of medium-low yield cropland was reduced from 291 250.13 hm2 in 1985 to 76489.87 hm2 in 2010, coming down 74% . In Tianjin, the area of medium- low yield farmland of 2010 accounted for 19% of the total cropland, of which the ratios of medium-low yield cropland of Jinghai County, Jixian County, Dagang of Binghai New Area, Wuqing District, Baodi District and Ninghe County were 43.12%, 18.59%, 17.23%, 14.01%, 7.05% and 0, respectively. Low soil nutrient content, drought and water shortage, soil salinization were the main yield limiting factors to medium-low yield cropland in Tianjin in 2010. The countermeasures to improve the medium- low yield cropland were proposed, involving enhancing the investment of the government, strengthening the construction of water conservancy infrastructure, further improving the soil fertility, as well as saline and alkaline land, optimizing the farming system and planting drought and salt tolerance crops, etc.