Effects of long-term repeated mineral and organic fertilizer applications on soil organic carbon and total nitrogen in a semi-arid cropland

2013 ◽  
Vol 45 ◽  
pp. 20-26 ◽  
Author(s):  
Zhou Zhengchao ◽  
Gan Zhuoting ◽  
Shangguan Zhouping ◽  
Zhang Fuping
2011 ◽  
Vol 114 (2) ◽  
pp. 165-174 ◽  
Author(s):  
Marco Mazzoncini ◽  
Tek Bahadur Sapkota ◽  
Paolo Bàrberi ◽  
Daniele Antichi ◽  
Rosalba Risaliti

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4758 ◽  
Author(s):  
Jiaoyang Zhang ◽  
Caili Sun ◽  
Guobin Liu ◽  
Sha Xue

BackgroundLong-term fertilisation has a large influence on soil physical and chemical properties in agro-ecosystems. The effects on the distribution of aggregates, however, are not fully understood. We determined the dynamic change of the distribution of aggregates and soil organic carbon (SOC) content over time in a long-term field experiment established in 1998 on the Loess Plateau of China and illustrated the relationship between them.MethodsWe determined SOC content and the distribution of aggregates in nine fertiliser treatments: manure (M); nitrogen (N); phosphorus (P); M and N; M, N, and P; M and P; N and P; bare land; and an unfertilised control. These parameters were then used for a path analysis and to analyse the fractal dimension (Dv).ResultsThe organic fertiliser increased SOC content. The proportions of 0.1–0.25 mm microaggregates and 0.25–0.5 mm macroaggregates were higher and the proportion of the 0.01–0.05 mm size class of the silt + clay fraction was lower in the treatments receiving organic fertiliser (M, MN, MNP, and MP) than that in the control, indicating that the addition of organic fertiliser promoted aggregation. The distribution of aggregates characterised by their fractal dimension (Dv), however, did not differ among the treatments.DiscussionDvwas strongly correlated with the proportion of the <0.002 mm size class of the silt + clay fraction that did not differ significantly among the treatments. The change in the distribution of aggregates was strongly correlated with SOC content, which could produce organic polymer binding agents to increase the proportion of larger particles. Long-term application of organic fertiliser is thus necessary for the improvement and maintenance of soil quality in semi-arid agricultural land when residues are removed.


2014 ◽  
Vol 1073-1076 ◽  
pp. 1743-1750
Author(s):  
Wei Guo ◽  
Zhong Qing Zhang ◽  
Jin Hua Liu ◽  
Ping Zhu ◽  
Jing Min Yang

Long-term experiment of Gongzhuling base for the study through three treatments(1)NPK: NPK fertilizer; (2)N165M: Manure and NPK fertilizer; (3)1.5M+NPK: 1.5Manure and NPK fertilizer, used DSSAT-Century soil model to study the long-term effects of different fertilizer treatments on soil organic carbon, total nitrogen content and the laws of growth and decline. The results show that: long-term application of nitrogen fertilizer can significantly improve crop yields compare with NPK.. Corn production is also affected by climatic conditions, especially in drought years with less precipitation. Larger impact of organic manure on soil organic carbon (SOC)and total nitrogen, SOC content obtained in descending order of 1.5M + N165> N165> N0 by Century model simulation. Soil organic carbon content and nitrogen content has a certain relevance, and the trend is consistent. Organic manure and inorganic fertilizer can significantly reduce soil inorganic nitrogen content and reduce the risk of nitrogen leaching. Through model simulations C / N ratio could be explained: C / N increases indicated an increase of organic carbon faster than organic nitrogen in soil, and changes of soil chronic library SOM2 determined organic carbon content. Therefore we should pay attention to organic manure carbon return level, vigorously promote the use of farmyard manure to improve soil nutrient content.


2014 ◽  
Vol 36 (4) ◽  
pp. 359 ◽  
Author(s):  
D. E. Allen ◽  
P. M. Bloesch ◽  
R. A. Cowley ◽  
T. G. Orton ◽  
J. E. Payne ◽  
...  

Fire and grazing are commonplace in Australian tropical savannas and the effects of these management practices on soil organic carbon stocks (SOC) is not well understood. A long-term (20 years) experiment studying the effects of fire on a grazed semi-arid tropical savanna was used to increase this understanding. Treatments, including frequency of fire (every 2, 4 and 6 years), season of fire [early (June) vs late (October) dry season] and unburnt control plots, were imposed on Vertosol grassland and Calcarosol woodland sites, which were grazed. Additionally long-term enclosures [unburnt (except the Calcarosol in 2001) and ungrazed since 1973] on each soil type adjacent to each site were sampled, although not included in statistical analyses. SOC stocks were measured to a soil depth of 0.3 m using a wet oxidation method (to avoid interference by carbonates) and compared on an equivalent soil mass basis. Significant treatment differences in SOC stocks were tested for, while accounting for spatial background variation within each site. SOC stocks (0–0.3 m soil depth) ranged between 10.1 and 28.9 t ha–1 (Vertosol site) and 20.7 and 54.9 t ha–1 (Calcarosol site). There were no consistent effects of frequency or season of fire on SOC stocks, possibly reflecting the limited statistical power of the study and inherent spatial variability observed. Differences in the response to frequency and season of fire observed between these soils may have been due to differences in clay type, plant species composition and/or preferential grazing activity associated with fire management. There may also have been differences in C input between treatments and sites due to differences in the herbage mass and post-fire grazing activity on both sites and changed pasture composition, higher herbage fuel load, and a reduction in woody cover on the Vertosol site. This study demonstrated the importance of accounting for background spatial variability and treatment replication (in the absence of baseline values) when assessing SOC stocks in relation to management practices. Given the absence of baseline SOC values and the potentially long period required to obtain changes in SOC in rangelands, modelling of turnover of SOC in relation to background spatial variability would enable management scenarios to be considered in relation to landscape variation that may be unrelated to management. These considerations are important for reducing uncertainty in C-flux accounting and to provide accurate and cost-effective methods for land managers considering participation in the C economy.


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