Estimation on subsidy for returning manure to the field considering environmental and economic benefits

Objectives Manure application cost is high due to large volume but low nutrient contents, limiting the return of manure to field. This study estimated the scope of subsidies for returning manure to the field through the quantification of environmental and economic benefits brought by manure application, to provide a new idea for the construction of a subsidy policy tailored for mechanized manure application.

Methods Through literature retrieval and data collation, we got a total of 2349 data points on China’s carbon emission right transaction price from 2021 to 2025, and 3910 data points on livestock and poultry manure carbon mass fraction, with the Xinjiang Production and Construction Corps and Beidahuang Group as the study areas using the steady-state method and Monte Carlo method, established organic carbon density changing rate scenarios for estimation based on these scenarios, the manure application rates, operation cost, environmental economic benefits and subsidy amounts were determined.

Results Under the scenario of a 4‰ changing rate in soil organic carbon density, the livestock and poultry manure carbon application rate in Xinjiang Production and Construction Corps was 1103.3−2764.4 kg/hm²; the results in the 1st, 2nd, 3rd, 13th and 14th divisions were relatively low, approximately 750.0−1023.5, 1072.7−1683.4, 980.1−1196.7, 968.8−1748.9 and 391.2−542.5 kg/hm², respectively. The livestock and poultry manure carbon application rate in Beidahuang Group was 4697.4−7525.2 kg/hm²; the results in Baoquanling, Qiqihar and Harbin were relatively low, approximately 3011.0−4701.5, 4179.1−5452.4 and 4085.1−6599.1 kg/hm², respectively. The transaction price of carbon emission rights in China from 2021 to 2025 showed a trend of “rising first and then falling”, approximately 58.7−89.7 yuan/t. The manure application operation cost in Xinjiang Production and Construction Corps and Beidahuang Group was 44.9−117.0 and 181.0−316.0 yuan/hm², respectively, the environmental economic benefits of livestock and poultry manure application were 6.1−12.5 and 18.0−30.8 yuan/hm², respectively.

Conclusions The incentive-based subsidy ranges for livestock and poultry manure application operations in Xinjiang Production and Construction Corps and Beidahuang Group are 44.9−117.0 and 181.0−316.0 yuan/hm², respectively. It is suggested that the government comprehensively consider factors such as soil carbon sequestration targets and climatic conditions to optimize subsidies for manure application to fields; and include manure spreaders for livestock and poultry in the list of agricultural machinery purchase subsidies, to enhance the level of mechanized manure application operations.