温州市水稻土壤pH值和养分特征与分级的调查分析

Investigation and analysis on characteristics and grading of pH value and nutrients of paddy soil in Wenzhou City

掌握耕地土壤养分状况是保障粮食生产和耕地质量建设的重要内容。该研究在2021—2022年采集了温州市6 477个水稻土耕层样品,分析了土壤pH值、有机质、水解氮、速效磷和速效钾含量,并根据第二次土壤普查分级标准对土壤养分分级进行了评价,为水稻土合理施肥和耕地质量管理提供科学依据。结果显示,温州市水稻土土壤pH值平均为5.61,酸性土壤(pH值4.5~5.5)占比达48.43%,与第二次土壤普查结果比较,土壤呈现明显的酸化趋势。土壤有机质、水解氮、速效磷和速效钾平均含量分别为33.30 g·kg^(-1)、123.49 mg·kg^(-1)、67.93 mg·kg^(-1)和162.36 mg·kg^(-1)。总体上,土壤有机质和水解氮以很丰富-中等等级为主体;速效磷和速效钾含量很丰富-丰富等级之和的占比分别为51.58%和38.11%,但仍有较大比例的土壤存在缺磷和缺钾问题,缺乏-极缺乏之和的比例为32.85%和40.32%。与第二次土壤普查结果比较,温州市水稻土有机质平均含量保持稳定,速效磷和速效钾含量均有显著的提高,平均分别比第二次土壤普查时提高了430%和68.25%。不同行政区的土壤pH值、有机质、水解氮、速效磷和速效钾含量和分级存在明显差异。分析表明,温州市水稻土肥力的主要障碍因子是土壤酸化,土壤磷富集和缺乏共存,土壤缺钾明显。因此,水稻土施肥应实现减氮施肥,阻控土壤酸化;根据养分区域分布规律平衡施肥,维持土壤养分平衡。

Mastering the soil nutrient status of cultivated land is an important part of ensuring food production and the construction of cultivated land quality.This study collected 6477 paddy soil samples from the topsoil layer in Wenzhou City from 2021 to 2022,analyzed soil pH value,organic matter,hydrolyzable nitrogen,available phosphorus,and available potassium content,and evaluated the soil nutrient classification based on the grading standards of the Second National Soil Census,providing a scientific basis for reasonable fertilizer application and cultivated land quality management in paddy fields.The results showed that the average soil pH value of paddy fields in Wenzhou City was 5.61,with 48.43%of the soil being acidic(pH 4.5-5.5),showing a significant acidification trend compared with the Second National Soil Census.The average contents of soil organic matter,hydrolyzable nitrogen,available phosphorus,and available potassium were 33.30 g·kg^(-1),123.49 mg·kg^(-1),67.93 mg·kg^(-1),and 162.36 mg·kg^(-1),respectively.Overall,the soil organic matter and hydrolyzable nitrogen were primarily in the very rich to intermediate levels;the proportions of the sum of the very rich to rich levels for available phosphorus and available potassium were 51.58%and 38.11%,respectively.However,there was still a significant proportion of soil with phosphorus and potassium deficiencies,with the combined proportion of the sum of lacking to lacking-extremely being 32.85%and 40.32%.Compared with the Second National Soil Census,the average content of organic matter in Wenzhou′s paddy fields remained stable,and the contents of available phosphorus and available potassium significantly increased,with the average increasing by 430%and 68.25%,respectively.There were obvious differences in soil pH value,organic matter,hydrolyzable nitrogen,available phosphorus,available potassium content,and levels among different administrative regions.The analysis showed that the main obstacles to the fertility of paddy fields in Wenzhou City were soil acidification,coexistence of soil phosphorus enrichment and deficiency,and obvious soil potassium deficiency.Therefore,the application of fertilizer in paddy fields should achieve reduced nitrogen application and prevent soil acidification;balanced fertilization should be carried out according to the regional distribution of nutrients to maintain soil nutrient balance.