Land-use changes from arable crop to kiwi-orchard increased nutrient surpluses and accumulation in soils

The potential environmental risk associated to nutrient surpluses after changing arable crops to kiwi-orchards was assessed in the Yujiahe catchment of Shaanxi, China. This was achieved by surveying 242 kiwi-orchards and 21 croplands and determining their nutrient inputs and outputs as well as the soil nutrient status for the over 2 years. The total inputs of nitrogen (N), phosphorus (P) and potassium (K) from fertilizers, manures, deposition, and irrigation in kiwi-orchards were 1201, 268 and 615 kg ha−1 yr−1, respectively, which were higher than the rates of 425, 59 and 109 kg ha−1 yr−1 in wheat-maize fields. The mean annual apparent nutrient surpluses in kiwi-orchards were 1081 kg N ha−1 yr−1, 237 kg P ha−1 yr−1 and 491 kg K ha−1 yr−1. Within comparison to the croplands, the soil organic matter (SOM) and total N (TN) in the topsoil (0–20 cm) increased in kiwi-orchards, and soil pH decreased. The average contents of Olsen-P, and available K in 0–20 cm soils of the orchards were 86 mg kg−1, and 360 mg kg−1, which were higher than recommended levels. The nitrate-N accumulation in the 0–100 cm and 0–200 cm soil layers in kiwi-orchards were 466 and 793 kg N ha−1, respectively. The high proportion of nitrate-N in deeper soil profiles of kiwi-orchards poses a great risk for nitrate leaching and subsequent ground water pollution. It is concluded that changing arable crops to kiwi-orchards increased the environmental burden of the catchment due to excessive fertilizer application in kiwi-orchards

Mitigation of diffuse water pollution from agriculture in England and China, and the scope for policy transfer

• To mitigate diffuse water pollution from agriculture (DWPA) in China, the right mix of complementary policy approaches is needed. • The public agricultural extension service is relatively well resourced and is the primary means available to mitigate DWPA. The extension service needs re-orientation and re-skilling to help farmers maintain and increase agricultural productivity whilst balancing this with environmental protection. A new ethos of input use efficiency and environmental stewardship of natural resources is needed, based on 2-way knowledge exchange with farmers. Four policies to achieve this are: 1. A ‘reference level’ of enforceable regulation for all large commercial farms is needed. This can be transposed from existing laws with appropriate variation by farming system and region. Intensive livestock units have the greatest potential to cause significant pollution and take first priority. Resources for monitoring and enforcement of regulation are limited, but as land transfer and farm consolidation continue in accord with local needs, regulations for use of manure and chemical fertiliser in arable systems can be developed for large farms. 2. For small farms monitoring and enforcement of regulations is difficult. Simple, locally well-adapted guidelines are needed. Adoption by farmers must be achieved through an accredited advisory and voluntary approach developed by the public agricultural extension service and its wider agricultural knowledge and innovation systems partners. 3. Targeted incentive payment schemes should be used strategically to protect water resources from DWPA in key locations. For example, payments for retirement, or low intensity use, of vulnerable land adjacent to watercourses or in aquifer recharge zones used for water supply. 4. To support these approaches more applied research is needed to build an accessible and comprehensive knowledgebase. This should span, for example, from methods for public participation, through design of regulation and incentive payments, to design and costing of farm best management practices and estimation of modelling coefficients empirically derived for conditions in China. • None of these approaches are completely absent from China and attempts at international policy transfer or ‘lesson-drawing’ must consider what can be better developed rather than what could commence. Innovation in farmer participation, advice provision, design of incentive schemes, data sharing and applied research are leading examples

Speciesistic Veganism: An Anthropocentric Argument

The paper proposes an anthropocentric argument for veganism based on a speciesistic premise that most carnists likely affirm: human flourishing should be promoted. I highlight four areas of human suffering promoted by a carnistic diet: (1) health dangers to workers (both physical and psychological), (2) economic dangers to workers, (3) physical dangers to communities around slaughterhouses, and (4) environmental dangers to communities-at-large. Consequently, one could ignore the well-being of non-human animals and nevertheless recognize significant moral failings in the current standard system of meat production

Greenhouse gas emissions from agricultural food production to supply Indian diets: Implications for climate change mitigation

Agriculture is a major source of greenhouse gas (GHG) emissions globally. The growing global population is putting pressure on agricultural production systems that aim to secure food production while minimising GHG emissions. In this study, the GHG emissions associated with the production of major food commodities in India are calculated using the Cool Farm Tool. GHG emissions, based on farm management for major crops (including cereals like wheat and rice, pulses, potatoes, fruits and vegetables) and livestock-based products (milk, eggs, chicken and mutton meat), are quantified and compared. Livestock and rice production were found to be the main sources of GHG emissions in Indian agriculture with a country average of 5.65 kg CO2eq kg-1 rice, 45.54 kg CO2eq kg-1 mutton meat and 2.4 kg CO2eq kg-1 milk. Production of cereals (except rice), fruits and vegetables in India emits comparatively less GHGs with <1 kg CO2eq kg-1 product. These findings suggest that a shift towards dietary patterns with greater consumption of animal source foods could greatly increase GHG emissions from Indian agriculture. A range of mitigation options are available that could reduce emissions from current levels and may be compatible with increased future food production and consumption demands in India

How will organic carbon stocks in mineral soils evolve under future climate? Global projections using RothC for a range of climate change scenarios

We use a soil carbon (C) model (RothC), driven by a range of climate models for a range of climate scenarios to examine the impacts of future climate on global soil organic carbon (SOC) stocks. The results suggest an overall global increase in SOC stocks by 2100 under all scenarios, but with a different extent of increase among the climate model and emissions scenarios. The impacts of projected land use changes are also simulated, but have relatively minor impacts at the global scale. Whether soils gain or lose SOC depends upon the balance between C inputs and decomposition. Changes in net primary production (NPP) change C inputs to the soil, whilst decomposition usually increases under warmer temperatures, but can also be slowed by decreased soil moisture. Underlying the global trend of increasing SOC under future climate is a complex pattern of regional SOC change. SOC losses are projected to occur in northern latitudes where higher SOC decomposition rates due to higher temperatures are not balanced by increased NPP, whereas in tropical regions, NPP increases override losses due to higher SOC decomposition. The spatial heterogeneity in the response of SOC to changing climate shows how delicately balanced the competing gain and loss processes are, with subtle changes in temperature, moisture, soil type and land use, interacting to determine whether SOC increases or decreases in the future. Our results suggest that we should stop looking for a single answer regarding whether SOC stocks will increase or decrease under future climate, since there is no single answer. Instead, we should focus on improving our prediction of the factors that determine the size and direction of change, and the land management practices that can be implemented to protect and enhance SOC stocks