Carbon and Nitrogen Fractions in Dryland Soil Aggregates Affected by Long-term Tillage and Cropping Sequence

Long term manuring and fertilizer experiments conducted in India showed declining trend in productivity even with the application of NPK fertilizers under modern intensive farming. Neither organic source alone nor inorganic fertilizers can achieve sustainability in crop production under intensive agriculture, where nutrient turnover in soilplant system is much higher. However, their combined use appeared promising in enhanced crop productivity besides improving soil fertility. The mineralization of carbon and nitrogen plays significant role in availability ofnutrients. However, the role of mineralization determines the flux of nutrient flow. When fertilizer nitrogen is added to the soil, the portion of it is immobilized, but the mineralization rate of recently immobilized fertilizer is greater than indigenous organic nitrogen. The rate of carbon and nitrogen mineralization is different for various cropping systems and hence, it is necessary to study mineralization. N-mineralization potential increases with increasing nitrogen rate in dryland and irrigation conditions. In order to investigate the long term influence of fertilization on soil labile carbon and N mineralization, the present study was undertaken in sorghum-wheat cropping sequence on Vertisol.

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Distribution and altitudinal patterns of carbon and nitrogen storage in various forest ecosystems in the central Yunnan Plateau, China

Scientific Reports ◽

10.1038/s41598-021-85710-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jianqiang Li ◽

Qibo Chen ◽

Zhuang Li ◽

Bangxiao Peng ◽

Jianlong Zhang ◽

...

Keyword(s):

Forest Ecosystems ◽

Sustainable Forest Management ◽

Carbon And Nitrogen ◽

Pinus Yunnanensis ◽

Yunnan Plateau ◽

Baseline Information ◽

C And N ◽

Quercus Semecarpifolia ◽

Management Policies

AbstractThe carbon (C) pool in forest ecosystems plays a long-term and sustained role in mitigating the impacts of global warming, and the sequestration of C is closely linked to the nitrogen (N) cycle. Accurate estimates C and N storage (SC, SN) of forest can improve our understanding of C and N cycles and help develop sustainable forest management policies in the content of climate change. In this study, the SC and SN of various forest ecosystems dominated respectively by Castanopsis carlesii and Lithocarpus mairei (EB), Pinus yunnanensis (PY), Pinus armandii (PA), Keteleeria evelyniana (KE), and Quercus semecarpifolia (QS) in the central Yunnan Plateau of China, were estimated on the basis of a field inventory to determine the distribution and altitudinal patterns of SC and SN among various forest ecosystems. The results showed that (1) the forest SC ranged from 179.58 ± 20.57 t hm−1 in QS to 365.89 ± 35.03 t hm−1 in EB. Soil, living biomass and litter contributed an average of 64.73%, 31.72% and 2.86% to forest SC, respectively; (2) the forest SN ranged from 4.47 ± 0.94 t ha−1 in PY to 8.91 ± 1.83 t ha−1 in PA. Soil, plants and litter contributed an average of 86.88%, 10.27% and 2.85% to forest SN, respectively; (3) the forest SC and SN decreased apparently with increasing altitude. The result demonstrates that changes in forest types can strongly affect the forest SC and SN. This study provides baseline information for forestland managers regarding forest resource utilization and C management.

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