title: Land use change influences soil C, N, and P stoichiometry under 'Grain-to-Green Program' in China.
abstract: Changes in land use might affect the combined C, N and P stoichiometry in soil. The Grain-to-Green Program (GTGP), which converts low-yield croplands or abandoned lands into forest, shrub, and/or grassland, was the largest land reforestation project in China. This study collected the reported C, N and P contents of soil in GTGP zones to achieve the factors driving the changes in the C:N, C:P, and N:P values. The results showed that the annual average precipitation exerted significant effects on the C:P value, and on the N:P value became significant 20 years after the change in land use. The annual average temperature was the main factor affecting the C:N value during the first 10 years, while the annual average precipitation strongly affected this value afterwards. In addition, "Redfield-like" interactions between C, N, and P in the soil may exist. A linear regression revealed significant positive correlations between the C:N, C:P, and N:P values and the restoration age, temperature, and precipitation after a change in land use. Therefore large-scale changes in land use under the 'GTGP' program might significantly affect the C:N, C:P and N:P ratios in soil.
authors.affiliation: 1] College of Agronomy, Northwest A&F University, Yangling, 712100 Shaanxi, China [2] The Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Yangling 712100 Shaanxi, China.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Fazhu
authors.affiliation: College of Life Science, Northwest A&F University, Yangling, 712100 Shaanxi, China.
authors.forename: Sun
authors.initials: S
authors.lastname: Jiao
authors.affiliation: 1] College of Agronomy, Northwest A&F University, Yangling, 712100 Shaanxi, China [2] The Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Yangling 712100 Shaanxi, China.
authors.forename: Ren
authors.initials: R
authors.lastname: Chengjie
authors.affiliation: 1] The Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Yangling 712100 Shaanxi, China [2] College of Forestry, Northwest A&F University, Yangling, 712100 Shaanxi, China.
authors.forename: Kang
authors.initials: K
authors.lastname: Di
authors.affiliation: 1] College of Agronomy, Northwest A&F University, Yangling, 712100 Shaanxi, China [2] The Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Yangling 712100 Shaanxi, China.
authors.forename: Deng
authors.initials: D
authors.lastname: Jian
authors.affiliation: 1] College of Agronomy, Northwest A&F University, Yangling, 712100 Shaanxi, China [2] The Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Yangling 712100 Shaanxi, China.
authors.forename: Han
authors.initials: H
authors.lastname: Xinhui
authors.affiliation: 1] College of Agronomy, Northwest A&F University, Yangling, 712100 Shaanxi, China [2] The Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Yangling 712100 Shaanxi, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Gaihe
authors.affiliation: 1] College of Agronomy, Northwest A&F University, Yangling, 712100 Shaanxi, China [2] The Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Yangling 712100 Shaanxi, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Yongzhong
authors.affiliation: 1] College of Agronomy, Northwest A&F University, Yangling, 712100 Shaanxi, China [2] The Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Yangling 712100 Shaanxi, China.
authors.forename: Ren
authors.initials: R
authors.lastname: Guangxin