Soil information for agricultural decision making: a New Zealand perspective

Understanding of the soil resource is pivotal to our ability to use, manage and modify soils effectively and responsibly. Yet those who make the most decisions concerning soil use and management – farmers and landholders – rarely have access to reliable soil information at scales suitable for farm decision making. By default, many rely on limited local soil knowledge when making decisions that determine farm performance and environmental impact. Providing detailed nationwide soil information that is appropriate for farm decision making is feasible, as demonstrated by the achievements of several European countries and the USA. For New Zealand, a stratified programme at scales of 1:10 000 for versatile land; 1:25 000 for other agricultural land; and 1:50 000 for non‐domesticated land, would cost NZD $280 million, or NZD $11.2 million per year if spread over the useful life of the information. This investment is small relative to the economic value of agriculture, and necessary if New Zealand is to make meaningful advances in reducing current agri‐environmental trends.     

A computerized soil information system for arable land in Japan

A computerized soil information system was compared to manual punch card methods for storage and retrieval of Japanese soil survey data. In spite of the high cost, a soil information system using computers is the most appropriate system for the future, because by this method more than three factors can be analyzed simultaneously, various kinds of soil map data can be stored, retrieved and updated and many kinds of interpretative maps can be constructed automatically. There are large amounts of valuable soil survey data available in Japan which previously were used only for drawing soil maps. These should be utilized to develop a computerized soil information system. At the end of this report, essential processes and the possible structure of a Japanese Soil Information System were discussed.     

土壤地下渗滤法处理分散生活污水的新技术: 两段厌氧土壤渗滤沟系统

The low removal efficiency of total nitrogen （TN） is one of the main disadvantages of traditional single stage subsurface infiltration system, which combines an anaerobic tank and a soil filter field. In this study, a full-scale, two-stage anaerobic tank and soil trench system was designed and operated to evaluate the feasibility and performances in treating sewage from a school campus for over a one-year monitoring period. The raw sewage was prepared and fed into the first anaerobic tank and second tank by 60% and 40%, respectively. This novel process could decrease chemical oxygen demand with the dichromate method by 89%-96%, suspended solids by 91%-97%, and total phosphorus by 91%-97%. The denitrification was satisfactory in the second stage soil trench, so the removals of TN as well as ammonia nitrogen （NH4^＋-N） reached 68%-75% and 96% 99%, respectively. It appeared that the removal efficiency of TN in this two-stage anaerobic tank and soil trench system was more effective than that in the single stage soil infiltration system. The effluent met the discharge standard for the sewage treatment plant （GB18918-2002） of China.     

为21世纪土壤科学的创新发展作出新的贡献——参加第17届国际土壤学大会综述

今年8月14～21日，在泰国曼谷召开了第17届国际土壤学大会，这是在21世纪首次举行的全球性的土壤科学学术盛会。在14日的开幕式上，泰国皇家王室M C Sirindhorn公主亲莅会场致开幕词，并为大会展览厅揭幕。曼谷市市长、泰国土地发展部部长、本届国际土壤学会主席及秘书长等人在     

A GIS based approach to modelling the effects of land-use change on soil erosion in New Zealand

Abstract. The problem of soil erosion is particularly evident in New Zealand, given the combination of coarse-textured soils, steep relief, high rainfall, and intensification of agriculture. A study was undertaken to assess the effects of land use change on soil erosion and sediment transport for the Ngongotaha catchment in New Zealand's North Island, using a GIS based decision support and modelling system. Model simulations considered the effect of increased catchment area under deer farming and forestry on the amount of sediment delivered to the catchment outlet, averaged over a period of six years. The simulations predicted that sediment loss from land under deer farming was considerably greater than from land under other livestock or forestry. Further model simulations testing best management practices demonstrated that sediment yield could be halved if deer farming was restricted to slopes under 20%.     

试论开发治理水土流失山区的方略

我国山区约占国土总面积的70%,自然资源十分丰富。治理和开发山区在国家经济建设中处于重要战略地他,应与重点开发沿海发达地区统筹兼顾,发挥各自优势,互相支援,互相促进,协调发展。山区水土流失严重,是山区贫困的根源,是山区开发的主要障碍。水土保持是防治水土流失,保护和合理利用山区水土资源,改善生态环境,减少自然灾害,发展多种商品经济,脱贫致富的战略措施;是山区交通、工矿等基本建设的根本保证和开发山区的基础。治理开发山区总的方向是:预防为主,治管结合,全面规划,综合治理,以发展多种经营为主,同时不放松粮食生产,尽快脱贫致富;还要把观念和职能,转到以预防为主,治管结合的轨道上来,加强以监督管理和法制来防治新的水土流失。同时还要依靠政策、科学和投入,特别要建立健全全国各级水土保持机构体系,以强化水土保持和山区开发,为我国社会主义现代化建设做出更大贡献。     

Role of wheel tracks in runoff generation and erosion under vegetable production on a clay loam soil at Pukekohe, New Zealand

The effects of wheel traffic on soil surface hydraulic properties, and consequent effects on erosion, following planting of vegetable crops in beds have not been widely studied. This paper describes two trials to quantify how wheel tracks influence infiltration and erosion rates, and assesses the value of cultivating wheel tracks for reducing erosion. The trials were carried out under natural rainfall, on Dystric Nitosols with clay loam texture and strong, stable structure. Net rates of erosion from onion (Allium cepa L.) beds with cultivated or uncultivated inter-bed wheel tracks were measured with erosion pins and repeat topographic surveys of sediment trapped in silt fences. Infiltration rates in onion beds, cultivated and uncultivated wheel tracks, and changes in infiltration rates through winter, spring, and summer, were measured using the double-ring, ponded-water method.

Differences in erosion rate were only measured in the second trial in which erosion rate from the uncultivated treatment was 21 Mg ha⁻¹, compared to 1 Mg ha⁻¹ for the cultivated treatment. Erosion occurred through mobilisation of soil along the edge and base of the wheel tracks, with no evidence of erosion of the onion beds. Most of the eroded soil comprised soil aggregates, with 75% between 0.25 and 4 mm in diameter, suggesting soil was transported in runoff along the wheel tracks as stable aggregates. Uncultivated wheel tracks had very low infiltration rates compared to onion beds and cultivated wheel tracks. The differences in infiltration rates between cultivated and uncultivated wheel tracks were consistent in both trials, with minor differences due to rainfall patterns and the implements used to cultivate wheel tracks. There were clear trends in infiltration rates through time, with rates in the uncultivated wheel tracks increasing during the growing season from 1.4×10⁻⁷ to 2.1×10⁻⁵ ms⁻¹ and in onion beds from 1.1×10⁻⁴ to 2.5×10⁻⁴ ms⁻¹, while rates in the cultivated wheel tracks decreased from 1.7×10⁻² to 2.4×10⁻³ ms⁻¹. The major increase of infiltration rate in uncultivated wheel tracks occurred after October when the soil surface began to dry out, and frequent wetting and drying cycles caused the compacted surface soil to crack. Most erosion occurred in the winter/early spring period when storm frequency and rainfall intensity was highest, and infiltration rates in the uncultivated wheel tracks lowest. Cultivating wheel tracks is a simple and effective practice to increase infiltration of rainfall and reduce erosion rates on clay-rich, strongly structured soils.     

红壤地区农业发展区划中土壤信息系统与交互式自组织数据的集成

Element contents of tree rings and soils near tree roots collected from Deodar cedar (Cedrus deodara (Roxb.) G.Don) and Masson pine(Pinus massoniana lamb).were determined to study the relationship between the angular distribution of element contents in tree rings and the environmental information.The chemical composition and properties of soil are very much cmoplicated,which leads to the non-uniform distribution of the element contents in tree rings.The statistical multi-varialbe regression method was used to get the information of the tree-centered distribution of element contents in the environment(soil),(C‘),C‘(Z,θj),from the distribtuion of element contents in tree rings(C),C(Z,θi),which depends on the plane azimuth angle(θi),i.e.,C=C(Z,θi),where Z is the atomic number of the element,with a satisfactory result though this study is only a primary one.     

Soil science contributions towards Sustainable Development Goals and their implementation: linking soil functions with ecosystem services

The United Nations effort to define Sustainable Development Goals (SDG's), emphasizing local goals and capacity building, offers a unique opportunity for soil science to demonstrate the role it can play when focusing on these goals. Several strategic reports have presented key issues for sustainable development: food security, freshwater and energy availability, climate change and biodiversity loss are issues most frequently being listed, not soil degradation. Focusing on soil contributions towards interdisciplinary studies of these key issues, rather than emphasizing soils by themselves, is therefore bound to be more effective for the soil science profession. But this is still inadequate when studying land‐related SDG's, requiring a broader ecosystem approach that can be achieved by a direct link between soil functions and corresponding ecosystem services. Thus, the key issues are not considered separately but linked as part of a dynamic ecosystem characterization following a narrative as is demonstrated for food security, that can be well addressed by precision agriculture. As all key issues and at least five of the ten SDG's are directly land‐related, soil science can potentially play an important role in the suggested interdisciplinary studies. But in addition, the current information society with knowledgeable stakeholders requires innovative and interactive transdisciplinary scientific approaches by not only focusing on knowledge generation but also on co‐learning with stakeholders and, important, on implementation. The soil science discipline can become more effective in the transdisciplinary context by: (1) reconnecting the knowledge chain, linking tacit with scientific knowledge both ways, (2) simplifying soil terminology, (3) learning to deal with “wicked” environmental problems for which no single solutions exist but only a series of alternative options for action, balancing economic, social and environmental considerations, (4) educating “knowledge brokers”, linking science with society in land‐related issues, acting within a “Community of Scientific Practice”, and (5) modernizing soil science curricula. Transdisciplinary approaches are crucial to achieve SDG's, linking science and society. There is a need for specific results on the ground illustrating with hard data the key role soils can play in realizing SDG's.     

Roots,rhizosphere and soil: the route to a better understanding of soil science?

The centenary of Hiltner's recognition of a rhizosphere effect is a convenient point to assess the impact of such thinking on the direction of soil science. A review of the major soil journals suggests that for much of the last century, Hiltner's insight had little effect on mainstream thinking outside of soil microbiology, but this situation is changing rapidly as the consequences of spatial and temporal heterogeneity on soil functioning assumes greater importance. Studies of root growth, root distributions and of rhizosphere processes over the last 25 years demonstrate both the size and distribution of root systems and the associated inputs from roots to soils. These inputs result in a plethora of dynamic reactions at the root–soil interface whose consequences are felt at a range of temporal and spatial scales. Root growth and respiration, rhizodeposition, and uptake of water and nutrients result in biological, chemical and physical changes in soils over variable distances from the root surface so that the rhizosphere has different dimensions depending on the process considered. At the root length densities common for many crop species, much of the upper 0.1 m of soil might be influenced by root activity for mobile nutrients, water and root‐emitted volatile compounds for a substantial proportion of the growing season. This brief review concludes that roots are an essential component of soil biology and of soil science.     

Soil landscape evolution due to soil redistribution by tillage: a new conceptual model of soil catena evolution in agricultural landscapes

This paper focuses on analysing tillage as a mechanism for the transformation of soil spatial variability, soil morphology, superficial soil properties and development of soil–landscape relationships in agricultural lands. A new theoretical two-dimensional model of soil catena evolution due to soil redistribution by tillage is presented. Soil profile truncation occurs through loss of soil mass on convexities and in the upper areas of the cultivated hillslopes; while the opposite effect takes place in concavities and the lower areas of the field where the original soil profile becomes buried. At sectors of rectilinear morphology in the hillslope (backslope positions), a null balance of soil translocation takes place, independent of the slope gradient and of the rate of downslope soil translocation. As a result, in those backslope areas, a substitution of soil material in the surface horizon with material coming from upslope areas takes place. This substituted material can produce an inversion of soil horizons in the original soil profile and sometimes, the formation of “false truncated soil”. In the Skogstad agricultural field (Cyrus, MN) spatial patterns of soil properties (soil calcium carbonate content) in the surface soil horizons and soil morphology along several slope transects were analyzed. These spatial patterns are compared with those estimated for soil redistribution (areas of erosion and deposition) due to tillage using the Soil Redistribution by Tillage (SORET) model and water erosion using the models Water Erosion Prediction Project (WEPP) and Universal Soil Loss Equation (Usle2D). Results show that tillage was the predominant process of soil redistribution in the studied agricultural field. Finally, some practical implications of the proposed model of soil landscape modification by tillage are discussed. Nomographs to calculated the intensity of the expansion process of the eroded soil units by tillage are proposed for three different patterns of tillage.