Abstract:

To better understand the fertilization status of farmers at the county scale in Guangdong, and then provide references for formulating scientific fertilizer management strategies and implementing soil testing and formulated fertilization as well as reducing chemical fertilizers and increasing efficiency, the data on crop planting and fertilization throughout the year of 124 farmers in five towns of Boluo County were collected in 2022 by field survey. The overall characteristics of fertilization were analyzed, and a detailed examination was conducted for the fertilization status, partial productivity and application reduction potential of three land use types (paddy fields, vegetable fields, and orchards). The results showed that the input of chemical fertilizer nutrients (N, P₂O₅, and K₂O) in Boluo County was 864.7 kg/hm², while the proportion of organic fertilizer application reached 42.7% and its nutrient input was 326.3 kg/hm². The chemical fertilizers were primarily compound fertilizers, among which the 1:1:1 type accounted for 72.5% of the total chemical fertilizer usage. Organic fertilizers were mainly commercial ones. In terms of fertilization methods, the base fertilizer was mainly applied deeply, while the additional fertilizer was applied superficially mainly. There were significant differences in fertilizer application rates among different land use types, with orchards having the highest nutrient input. Specifically, the nutrient inputs of chemical fertilizers were 580.7, 717.5, and 1051.6 kg/hm² for paddy fields, vegetable fields, and orchards respectively, while the nutrient inputs of organic fertilizers were 37.6, 327.6, and 598.5 kg/hm² respectively. Among farmers using organic fertilizers, the nutrient substitution rates of organic fertilizers in paddy fields, vegetable fields and orchards were 4.6%, 30.3% and 34.9%, respectively. The partial factor productivity of fertilizer nutrients in paddy fields, vegetable fields and orchards was 17.3, 59.7, and 15.1 kg/kg, respectively, and the potential for fertilizer nutrient reduction was estimated to be 49.4%, 33.4%, and 34.7%, respectively. There was an imbalance in the proportion of nitrogen, phosphorus, and potassium nutrient inputs in paddy fields and vegetable fields, with phosphorus overuse being the most significant in vegetable fields. Currently, there are problems such as high fertilizer usage, unbalanced nutrient ratio and backward fertilization methods in Boluo County. It is recommended to reasonably adjust the amount of fertilizer applied to crops, and control the input ratio of phosphorus in order to improve the utilization rate of fertilizers, reduce unnecessary fertilizer waste and promote the sustainable development of agricultural production.

Key words: Guangdong Province, Boluo County, farmers survey, fertilizer status, crops, nutrient input, partial factor productivity, reduction potential