Welcome to a special issue of the Journal of the Science of Food and Agriculture with selected papers presented at the 2nd International Symposium on Sustainable Agriculture in Sub-tropical Regions (ISSASR-2) held in Changsha, Hunan Province, China in September 2010. This symposium gathered over 70 scientists from 17 countries and international organizations to discuss the key issues on soil and water resources, and their management, rapidly developing intensive crop and animal production systems, their impacts on global changes and environments, as well as the political and technological requirements to sustain resources and agricultural production systems in subtropical regions worldwide.

This Special Issue opens with a mini-review and two review articles focusing on some key issues of fertilizer use and soil constraints in subtropical regions of China and the world. The mini-review by Chen et al.1 highlights aluminium (Al) toxicity and phosphorus (P) deficiency as the main constraints which largely affect the yields and quality of crops grown in acid soils in subtropical regions, and recommends some remediation measures which are widely used in tropical and subtropical regions. Then, Fixen and Johnston2 introduce the development and implementation of best management practices for fertilizer applications, with focus on the 4Rs—right source, right rate, right time, right place—not only for short-term economic and environmental reasons, but also for the wise stewardship of the non-renewable nutrient resources upon which food, feed, fiber, and fuel production depend. The next paper by Jin3 is a review on fertilizer use efficiency (which has significantly declined since 1990), based on serial field trials in China, and discusses the measures to improve fertilizer use in China.

The next three papers are also reviews but focus on aspects of animal production. Integrated crops and livestock are efficient production systems in the subtropical region, especially due to the land limitations for animal production, as emphasized by Wright et al.4, who also draw attention to the urgent requirements of appropriate technologies to sustain animal production in developing countries. Zhang et al.5 draw attention to the main challenges of pig production and Liu et al.6 add the need to strategically re-structure the industries of herbivores and other domestic species, and to develop sustainable faming systems based on the available feed sources in subtropical China.

Selected articles reporting original research in subtropical soil-crop systems contribute new knowledge on soil water and nutrient management and their potential impacts on global changes, environments and soil microbial functions. An important finding by Wu et al.7 reveal that the mineralization of fresh organic materials can significantly be restricted in paddy soils, and this consequently benefits carbon sequestration. Ji et al.8 provide an excellent example for the improved management of rice straw in double rice systems for carbon sequestration and controlling methane emissions. With an intensive survey of nitrogen flow in Changjiang River Basin, China, Liu et al.9 highlight the environmental risks caused by the overuse of chemical fertilizers and poor management of human and animal slurry to rural areas and rivers. However, an integrated watershed management approach was introduced by Wani et al10, based on field studies in the tropical region of India, which can enable farmers to diversify the systems along with increasing agricultural productivity through increased water availability, while conserving the natural resources. Chen et al.11 report a novel study on the impacts of various fertilizers on the size and composition of the nosZ-denitrifier community in paddy soils, while Ding et al.12 present strong evidence for the microbial mobilization of absorbed phosphorus induced by rice straw in aggregates of a highly weathered upland soil in China, and propose that the microbial mobilization can play an important role in crop demand for phosphorus in P-deficient soils. Surprisingly, Jetiyannon and Plianbangchang13 show sound results using the rhizobacterium strain RS87 to improve rice productivity with a 50% cut in fertilizer inputs in Thailand.

A set of four articles reporting original research on reclamation of degraded karst soils, which are widespread ecologically fragile lands in subtropical China and in many other countries, were also selected in this Special Issue. Chen et al.14 present results on the changes in soil organic carbon and total nitrogen, while Zhang et al.15 analyze the spatial distribution of organic carbon changes using NDVI analyses. He et al.16 describe the responses of soil microbial communities and bacterial metabolic profiles to the reclamation, and an additional study by Hu et al.17 shows that calcium carbonate, which is largely present in karst soils, plays an important role to stabilize soil organic carbon.

The applications of models in water and nutrient managements were also discussed in two articles. Wang et al.18 report significant work using a Soil and Water Assessment Tool (SWAT) model to simulate the water cycle coupled with the distribution, movement and transformation of nutrients on watersheds, and recommend the reforestation of cultivated land as an effective measure for watershed environment management. In a further application of the Water and Nitrogen Management Model (WNMM), Li et al.19 simulate the response of nitrous oxide emissions to fertilizer nitrogen application and climatic variability from a rain-fed and wheat-cropped soil in Western Australia.

We would like to express a dedication to the long and distinguished memory of Professor J. Keith Syers, a world outstanding scientist in soil and agriculture, and the Co-Chair of ISSASR-2. We would like to thank him for his great contribution to ISSASR-1, ISSASR-2, and his help in the preparation of this Special Issue.

We would also like to announce that the Institute of Subtropical Agriculture will sponsor the third International Symposium on Sustainable Agriculture in Sub-tropical Regions (ISSASR-3), which is proposed to be held in 2014.

Finally, a big thank you to all the participants of ISSASR-2, Prof. Kelin Wang (the president of ISSASR-2), and the members of the ISSASR-2 committees for their invaluable contribution to the success of this international meeting.


  1. Top of page
  • 1
    Chen RF, Zhang FL, Zhang QM, Sun QB, Dong XY and Shen RF, Aluminium–phosphorus interactions in plants growing on acid soils: does phosphorus always alleviate aluminium toxicity? J Sci Food Agric 92: 9951000 (2012).
  • 2
    Fixen PE and Johnston AM, World fertilizer nutrient reserves: a view to the future. J Sci Food Agric 92: 10011005 (2012).
  • 3
    Jin JY, Changes of fertilizer use efficiency in China. J Sci Food Agric 92: 10061009 (2012).
  • 4
    Wright IA, Tarawali S, Blümmel M, Gerard B, Teufel N and Herrero M, Integrating crops and livestock in subtropical agricultural systems. J Sci Food Agric 92: 10101015 (2012).
  • 5
    Zhang YG, Yin YL, Fang J and Wang Q, Pig production in subtropical agriculture. J Sci Food Agric 92: 10161024 (2012).
  • 6
    Liu SM, Cai YB, Zhu HY and Tan ZL. Potential and constraints in the development of animal industries in China. J Sci Food Agric 92: 10251030 (2012).
  • 7
    Wu J, Zhou P, Li L, Su YR, Yuan HZ and Syers JK, Restricted mineralization of fresh organic materials incorporated into a subtropical paddy soil. J Sci Food Agric 92: 10311037 (2012).
  • 8
    Ji XH, Wu JM, Peng H, Shi LH, Zhang ZH, Liu ZB, et al, The effect of rice straw incorporation into paddy soil on carbon sequestration and emissions in the double cropping rice systems. J Sci Food Agric 92: 10381045 (2012).
  • 9
    Liu C, Wang QX, Yang YH, Wang KL, Zhu OY, Li Y, et al, Recent trends of nitrogen flow of typical agro-ecosystems in China—major problems and potential solutions. J Sci Food Agric 92: 10461053 (2012).
  • 10
    Wani SP, Yin D, Li Z, Dar WD and Chander G, Enhancing agricultural productivity and rural incomes through sustainable use of natural resources in the Semi Arid Tropics. J Sci Food Agric 92: 10541063 (2012).
  • 11
    Chen Z, Hou HJ, Zheng Y, Qin HL, Zhu YJ, Wu J, et al, Influence of fertilisation regimes on a nosZ-containing denitrifying community in a rice paddy soil. J Sci Food Agric 92: 10641072 (2012).
  • 12
    Ding LJ, Wu J, Xiao H, Zhou P and Syers JK, Mobilisation of inorganic phosphorus induced by rice straw in aggregates of a highly weathered upland soil. J Sci Food Agric 92: 10731079 (2012).
  • 13
    Jetiyanon K and Plianbangchang P, Potential of Bacillus cereus strain RS87 for partial replacement of chemical fertilisers in the production of Thai rice cultivars. J Sci Food Agric 92: 10801085 (2012).
  • 14
    Chen HS, Zhang W, Wang KL and Hou Y, Soil organic carbon and total nitrogen as affected by land use types in karst and non-karst areas of northwest Guangxi, China. J Sci Food Agric 92: 10861093 (2012).
  • 15
    Zhang W, Wang KL, Chen HS, He XY and Zhang JG, Ancillary informaion improves kriging on soil organic carbon data for a typical karst peak cluster depression landscape. J Sci Food Agric 92: 10941102 (2012).
  • 16
    He XY, Su YR, Liang YM, Chen XB, Zhu HH and Wang KL, Land reclamation and short-term cultivation change soil microbial communities and bacterial metabolic profiles. J Sci Food Agric 92: 11031111 (2012).
  • 17
    Hu LN, Su YR, He XY, Wu J, Zheng H, Li Y, et al, Response of soil organic carbon mineralization in typical Karst soils following the addition of 14C-labeled rice straw and CaCO3. J Sci Food Agric 92: 11121118 (2012).
  • 18
    Wang QX, Xiao QA, Liu C, Wang KL, Ye M, Lei A, et al, Effect of reforestation on nitrogen and phosphorus dynamics in the catchment ecosystems of subtropical China: the example of the Hanjiang River basin. J Sci Food Agric 92: 11191129 (2012).
  • 19
    Li Y, Barton L and Chen D, Simulating response of N2O emissions to fertiliser N application and climatic variability from a rain-fed and wheat-cropped soil in Western Australia. J Sci Food Agric 92: 11301143 (2012).