Effects of Corridor Networks on Plant Species Composition and Diversity in an Intensive Agriculture Landscape

The development of modern agriculture has resulted in much homogenization of the landscape consisting of large patches of farmland,so small remnant non-crop habitats especially linear corridors play an important role in the conservation of species and the maintenance of ecosystem functions.However,little attention has been paid to the effects of corridors structural characteristics on the plant species restricted to such habitats.In this study,we selected three types of corridors including ditch,hedgerow and road,and analyzed their structural characteristics.The plant species presented in these corridors were investigated,and the species diversity,abundance and frequency were estimated.Moreover,spatial arrangements of corridors were classified into different types to discuss whether there were significant effects of corridor network on plant distribution.The results show that three types of corridors have different effects on plant species composition and diversity.The one-one combined corridor networks and total network associated by three corridors have more complex structural features than each single type of corridor.However,there is no strong correlation between the corridor networks with their plant species.We suggest that carrying out a pointed vegetation survey at corridor intersections to further test the relationships between structural features of corridor and plants is necessary.

Application of Arbuscular Mycorrhizae Glomus iranicum var. tenuihypharum var. nova in Intensive Agriculture： A Study Case

Intensive agriculture contributes to a decrease in microbial biomass and crop yields, while accelerating soil degradation. Arbuscular mycorrhizae associations have direct benefits for plant nutrition, and may be considered a useful tool in modem agriculture. Notwithstanding the widespread knowledge of these benefits, their use in intensive fanning systems has until now been ineffectual, because most mycorrhizal species have low tolerance toward high concentrations of nutrients and are poorly adapted to the soil and/or mycorrhizal functioning. The aim of this work was to test the efficacy of an arbuscular mycorrhizal （AM） fungus, Glomus iranicum var. tenuihypharum on lettuce and table grape crops in different intensive farming systems. The variables studied were root colonization percentage, external mycelium concentration, gas exchange, photosynthetic activity, root starch concentration and plant nutrition. The main finding was that the fungus is tolerant of a wide range of soil pH values, high salinity levels and abundant external mycelium. In lettuce, it produced significant increases in plant physiological activity and productivity （10%-15%）; and in table grapes, increases of 12%-45% in yield were achieved for more than three years in Crimson variety, and significant increases in fruit cluster weight, color uniformity and Brix （~Bx）. The AM species is protected by two patents and is a component of MycoUp, MycoUp Activ, Resid HC and Resid MG, whose commercial application has spread to more than 30 countries, with increments in crop yields of 8%-45% in lines as varied as leaf vegetables, berries, fruit, olives, grapes, greenhouse crops and cereals.

Global and Regional Surface Nitrogen Balances in Intensive Agricultural Production Systems for the Period 1970-2030

Global nitrogen (N) budgets for intensive agricultural systems were compiled for a 0.5 by 0.5 degree resolution. These budgets include N inputs (N fertilizer, animal manure, biological N fixation and atmospheric N deposition) and outputs (N removal from the field in harvested crops and grass and grass consumption by grazing animals, ammonia volatilization,denitrification and leaching). Data for the historical years 1970 and 1995 and a projection for 2030 were used to study changes in the recovery of N and the different loss terms for intensive agricultural systems. The results indicate that the overall system N recovery and fertilizer use efficiency slowly increased in the industrialized countries between 1970 and 1995, the values for developing countries have decreased in the same period. For the coming three decades our results indicate a rapid increase in both the industrialized and developing countries. High values of ＞ 80% for fertilizer use efficiency may be related to surface N balance deficits, implying a depletion of soil N and loss of soil fertility. The projected intensification in most developing countries will cause a gradual shift from deficits to surpluses in the coming decades.The projected fast growth of crop and livestock production, and intensification and associated increase in fertilizer inputs will cause a major increase in the surface N balance surplus in the coming three decades. This implies increasing losses of N compounds to air (ammonia, nitrous oxide and nitric oxide), and groundwater and surface water (nitrate).

Agricultural intensity for sustainable regional development:A case study in peri-urban areas of Karawang Regency,Indonesia

Peri-urban areas are playing an increasingly crucial role in the agricultural development and intensification in Indonesia.Peri-urban agriculture is highly vulnerable to change compared with urban and rural agriculture,due to its location in transitional areas.Indicators of peri-urban agricultural intensity can help guide regional development.In this study,we assessed the sustainability of peri-urban areas based on agricultural intensity in Karawang Regency,Indonesia.We developed a village-based index to assess the region’s agricultural intensity by rescaling the village agriculture index(VAI)and combining the local sustainability index(LSI)with factor analysis.Since the unit of analysis is the village,we modified the LSI to the village sustainability index(VSI).In addition,we also developed a logical matrix analysis to determine the level of agricultural sustainability(LoAS)of each village.The combined results of the three indices(VAI,VSI,and LoAS)generated information about agricultural sustainability.The results indicated that peri-urban villages with high agricultural intensity tended to exhibit low levels of social welfare,economic development,and disaster risk.Moreover,high agricultural intensity did not necessarily ensure the prosperity of the people.Instead,there was the economic disparity among the villages in the study area.Encouraging diversity of agricultural intensity seems to be more critical than promoting agricultural intensity itself.Overall,this study highlights the distinctive characteristics and dynamic of peri-urban areas.New approaches,variables,and information regarding the combination of agricultural intensity and sustainability need to be developed as valuable tools for regional planning.

Critical Soil Phosphorus Values for Yield Reduction in Intensive Agricultural Systems

Phosphorus(P)is an essential element for agricultural production.Over-fertilization during decades caused an accumulation of P in soils leading to eutrophication in regions characterized by intensive agriculture.These environmental concerns together with the non-renewability of P resources have led to a more sustainable P use.Knowledge about the P need of crops is essential for a sustainable agriculture thereby minimizing P losses to the environment without lowering the yield substantially.Therefore,in this study,critical soil P values for yield reduction(PCrit)were determined based on fertilizer trials conducted between 1970 and 1988 and more recent fertilizer trials(2016-2017).At rotational level a common PCrit value of 109 mg P/kg dry soil(in an ammonium lactate and acetate extract)was determined.Crop specific PCrit values were also determined for seven crops(potato,winter wheat,barley,rye,maize,sugar beet and temporary grassland).These critical values ranged from 59 mg P/kg dry soil to 164 mg P/kg dry soil with winter wheat the least and maize the most sensitive towards P deficiency.The diversity in PCrit values among crops can mainly be explained by the root intensity but also rooting depth,exudation of organic acids and phosphatases may influence the PCrit value.The soil pH also influenced the P availability significantly.Soils with a favorable pH had a significantly higher availability(i.e.,lower PCrit value)for all crops compared to soils with a suboptimal pH.Critical soil P values might help to set up new or to evaluate current soil P in target zones used for P fertilizer recommendations.

Intensive Agricultural Practices as Enhancers of the Dispersion of Invasive Species:Notification of the Observation of a Case with Robinia pseudoacacia L.in Alentejo(Southern Portugal)

Invasive forest species are a recurring problem,which in Portugal assume a somewhat mediatic role,both because of the impacts they cause on biodiversity,but also because they enhance the accumulation of high amounts of fuel load,increasing the risk of forest fires.However,in some areas of the country,such as the Alentejo(South of Portugal),the scarcity of water did not allow,until now,the dispersion and rapid growth of some of these species,namely Robinia pseudoacacia,which has always remained under control,and it was never a real problem.However,with the growth of intensive farming practices,associated with vineyards,olive groves and almond trees,water and nutrients became available,enabling this species to grow and disperse.This communication presents an observation of several sets of R.pseudoacacia specimens growing with different agricultural holdings,raising the hypothesis that intensive farming practices may,in the short term,contribute to the dispersion of invasive species in regions where they were not a problem,if the situations reported are not followed up and studies are carried out to confirm the observations described.

Phosphorus losses via surface runoff in rice-wheat cropping systems as impacted by rainfall regimes and fertilizer applications

Phosphorus（P） losses from agricultural soils contribute to eutrophication of surface waters. This field plot study investigated effects of rainfall regimes and P applications on P loss by surface runoff from rice（Oryza sativa L.） and wheat（Triticum aestivum L.） cropping systems in Lake Taihu region, China. The study was conducted on two types of paddy soils（Hydromorphic at Anzhen site, Wuxi City, and Degleyed at Xinzhuang site, Changshu City, Jiangsu Province） with different P status, and it covered 3 years with low, high and normal rainfall regimes. Four rates of mineral P fertilizer, i.e., no P（control）, 30 kg P ha^（–1） for rice and 20 kg P ha^（–1） for wheat（P_（30＋20））, 75 plus 40（P_（75＋40））, and 150 plus 80（P_（150＋80））, were applied as treatments. Runoff water from individual plots and runoff events was recorded and analyzed for total P and dissolved reactive P concentrations. Losses of total P and dissolved reactive P significantly increased with rainfall depth and P rates（P〈0.0001）. Annual total P losses ranged from 0.36–0.92 kg ha^–1 in control to 1.13–4.67 kg ha^–1 in P150＋80 at Anzhen, and correspondingly from 0.36–0.48 kg h^–1 to 1.26–1.88 kg ha^–1 at Xinzhuang, with 16–49% of total P as dissolved reactive P. In particular, large amounts of P were lost during heavy rainfall events that occurred shortly after P applications at Anzhen. On average of all P treatments, rice growing season constituted 37–86% of annual total P loss at Anzhen and 28–44% of that at Xinzhuang. In both crop seasons, P concentrations peaked in the first runoff events and decreased with time. During rice growing season, runoff P concentrations positively correlated（P〈0.0001） with P concentrations in field ponding water that was intentionally enclosed by construction of field bund. The relative high P loss during wheat growing season at Xinzhuang was due to high soil P status. In conclusion, P should be applied at rates balancing crop removal（20–30 kg P ha^–1 in this study） and at time excluding heavy rains. Moreover, irrigation and drainage water should be appropriately managed to reduce runoff P losses from rice-wheat cropping systems.

Agricultural Non-point Source Pollution in China:Evaluation,Convergence Characteristics and Spatial Effects

In this study,an inventory analysis approach was used to investigate the intensity of agricultural non-point source pollution(ANSP)and its spatial convergence at national and provincial levels in China from 1999 to 2017.On this basis,spatial factors affecting ANSP were explored by constructing a spatial econometric model.The results indicate that:1)The intensity of China's ANSP emission showed an overall upward trend and an obvious spatial difference,with the values being high in the eastern and central regions and relatively low in the western region.2)Significant spatial agglomeration was shown in China's ANSP intensity,and the agglomeration effect was increasing gradually.3)In the convergence analysis,a spatial lag model was found applicable for interpretation of the ANSP intensity,with the convergence rate being accelerated after considering the spatial factors but slower than that of regional economic growth.4)The spatial factors affecting the ANSP intensity are shown to be reduced by improving agricultural infrastructure investment,labor-force quality,and crop production ratio,while the expansion of agricultural economy scale and precipitation and runoff have positive impact on ANSP in the study region.However,agricultural research and development(R&D)investment showed no direct significant effect on the ANSP intensity.Meanwhile,improving the quality of the labor force would significantly reduce the ANSP intensity in the surrounding areas,while the precipitation and runoff would significantly increase the pollution of neighboring regions.This research has laid a theoretical basis for formulation and optimization of ANSP prevention strategies in China and related regions.

Biotechnological Strategies for Phytoremediating Triazinic Herbicides in the Humid Pampa （Argentine）

In agricultural producer countries, the use of chlorinated herbicides （atrazine）, associated to intensive farming practices, overflows the ecosystems natural attenuation capacity. Thus, herbicide residues contaminate the soils and water sources, increasing the risk for human health and wildlife. Humid Pampa is the main agricultural region in one of the world＇s largest herbicide consumer countries; hence, technologies to remediate its residues are needed. In this context, phytoremediation is an effective, environmental friendly and publicly accepted option. Accordingly, the objective of designing biotechnological strategies for phytoremediating triazinic herbicide residues in an integrated approach to the ongoing Humid Pampa agricultural trend is raised. In this way, strategies according to the edaphic, topogeographic and fanning practices characteristics of this region where established. In those strategies, the adequate selection of plant species is essential. For that purpose, atrazine tolerance assays were performed in simple （semisolid agar medium） and complex （microcosms） experimental systems implanted with Lolium multiflorum, Lotus sp. and Quenopodium quinoa. L. multiflorum was selected and evaluated via atrazine dissipation assays with soil. Atrazine soil content was determined by solvent extraction and subsequent HPLC-UV analysis, observing statistically significant attenuation levels at 21 days. According to the observed results, a strategy for scaling up the application to field conditions is proposed.

Spatial Spillover Effects of the Impact of Agricultural Mechanization on Carbon Emission Intensity in Agriculture:An Empirical Study Based on the Panel Data of 282 Cities

The extreme weather caused by the global warming effect has triggered huge losses to agricultural production.A hot issue for governments and scholars is how to effectively reduce carbon emission intensity in agriculture.The agricultural farming practices that are high pollution and high energy cosuming have exacerbated the vulnerability of regional agroecosystems.The sustainable development of agriculture is faced with the two dilemmas of a low utilization rate of green resources and the serious pollution of farmland.Further,environmental and ecological carrying capacities have reached theirlimits,seriouslyhinderingtthe high-quality development of low-carbon agriculture in China.Thus,based on the panel data of 282 cities,the Spatial Dubin Model(SDM)is employed to examine the impact of agricultural mechanization on carbon emission intensity in agriculture.It is found that from 1999 to 2019 carbon emission intensity in agriculture showed an overall downward trend;as of 2019,the agricultural field had completed the target of carbon emission reduction,,oneyear aheadof schedule.From a local perspective,approximately 14.89%6of fagricultural industries in prefecture-level city have still not achieved carbon emission reduction targets,and agricultural carbon emission reduction tasks were better completed in major grain-producing areas than in nonmajor grain-producing areas.Agricultural mechanization has significantly reduced carbonemission intensityyinlocal agriculture production.The impact of agricultural mechanizationoncarbon emission intensity in agriculture has not only a significant negative spatial spillover effect but also a significant effect on spatial carbon emission reduction.Compared with non-major ggrain-producingareas,agricultural mechanization plays a greater role in reducing spatial carbon emissions in major grain-producing areas.Further studies find that agricultural mechanization is conducive to overcome difficulties,such as instability of property rights and land fragmentation,and to achieve large-scale agricultural production,thereby reducing agricultural carbon emissions in nearby regions.However,the transfer of rurallabor,adjustments to the structure of agricultural cultivation,and the centralized use of rural land restrict the development of the crossregional service market for agricultural machinery,which in turn weaken its contribution to spatial carbon emission reduction.At the end of this paper,it is suggested that Chinese governments at all levels should introduce subsidy policies for the cross-regional operation of agricultural machinery to solve the problem of their service market failure.Efforts should be made to stimulate the market to develop more energy-efficient and environmentally friendly agricultural machinery products while strictly controlling changes in the use of arableland in non-grain-producing areas,which aims to serve further agricultural mechanization and boost the high-quality development of low-carbon agriculture.

Surface N balances and reactive N loss to the environment from global intensive agricultural production systems for the period 1970-2030

Data for the historical years 1970 and 1995 and the FAO-Agriculture Towards 2030 projection are used to calculate N inputs (N fertilizer, animal manure, biological N fixation and atmospheric deposition) and the N export from the field in harvested crops and grass and grass consumption by grazing animals. In most industrialized countries we see a gradual increase of the overall N recovery of the intensive agricultural production systems over the whole 1970-2030 period. In contrast, low N input systems in many developing countries sustained low crop yields for many years but at the cost of soil fertility by depleting soil nutrient pools. In most developing countries the N recovery will increase in the coming decades by increasing efficiencies of N use in both crop and livestock production systems. The surface balance surplus of N is lost from the agricultural system via different pathways, including NH3 volatilization, denitrification, N2O and NO emissions, and nitrate leaching from the root zone. Global NH3-N emissions from fertilizer and animal manure application and stored manure increased from 18 to 34 Tg·yr-1 between 1970 and 1995, and will further increase to 44 Tg·yr-1 in 2030. Similar developments are seen for N2O-N (2.0 Tg·yr-1 in 1970, 2.7 Tg·yr-1 in 1995 and 3.5 Tg·yr-1 in 2030) and NO-N emissions (1.1 Tg·yr-1 in 1970, 1.5Tg·yr-1 in 1995 and 2.0 Tg·yr-1 in 2030).

Spatiotemporal changes and influencing factors of the intensity of agricultural water footprint in Xinjiang, China

Xinjiang Uygur Autonomous Region,the largest agricultural high-efficiency water-saving arid area in China,was adopted to explore the coupling relationship between agricultural water consumption and economic benefits,which is of great significance to guiding the efficient utilization and sustainable development of agricultural water resources.This study utilizes an indicator,termed the Agricultural Water Footprint Intensity(short as AWFI,which means the amount of water resource consumed per unit of agricultural GDP),to study the economic benefits of agricultural water in Xinjiang from 1991-2018.In addition,the Theil index,a measure of the imbalance between individuals or regions,was used to study the evolution in the spatial differences in water efficiency,and the Logarithmic Mean Divisia Index(LMDI)method was applied to quantify the factors driving the AWFI.The results showed that AWFI in Xinjiang has experienced three stages:obvious decline,stable and slow decline,which decreased from 16114 m^(3)/10^(4) CNY to 2100 m^(3)/10^(4) CNY,decreasing by 86.97%.The Theil index indicated that the spatial evolution of 14 prefectures(cities)resembled an inverted N-shaped Kuznets curve over time.Among the influencing factors,the contributions of water-saving technology and planting structure to the change in the AWFI in Xinjiang,China from 1991 to 2018 were 154.03%and−37.98%,respectively.The total contribution to AWFI of the total population,urbanization rate,and production scale was−16.06%.This study concluded that further improvements in the economic benefits of agricultural water consumption can be obtained by continuing to promote more efficient or“water-conservation”irrigation technologies(engineering aspects),adjusting the planting structure(policy guidance aspects),and intensive management of cultivated land(management aspects).

Agricultural Land Use Intensity and Its Determinants in Ecologically-vulnerable Areas in North China:A Case Study of Taipusi County,Inner Mongolia Autonomous Region

Based on rural household survey data in Taipusi County in Inner Mongolia Autonomous Region, this article analyzes agricultural land use intensity and its determinants. The results reveal marked differences of agricultural land use intensity among households with different ages of householders, proportion of non-farm participants, total agricultural land area, land fragmentation and land utilization capacity. （i） Households with older householders and households with a smaller proportion of non-farming laborers generally spend more time on managing their land and invest less capital and materials than other households. The proportion of non-farming laborers within younger households is relatively high, and they tend to invest more capital and materials because the income derived from non-farm employment relaxes their financial constraints. （ii） Land fragmentation is an important determinant of land use intensity. Households with a bigger land size per plot usually spend less time and invest more capital and materials on their land; （iii） Land with better quality is usually managed intensively. The results suggest that labor has become an important constraint for local agricultural production, and there is the potential to improve land management scale and increase machinery input to substitute for labor. Furthermore, the effects of non-farm employment on land use intensity indicate that the establishment of a coordination mechanism between non-farm employment and agricultural land use is an important way to solve the conflict between ecological security and agricultural production in ecologically-vulnerable areas.

Abandonment of croplands: problem or chance for grassland restoration? Case studies from Hungary

In Central-and Eastern Europe,the collapse of socialist regimes resulted in a transformation of state-owned agricultural cooperatives to privately owned lands from the early 1990s onwards.These socioeconomic processes resulted in landscape-scale changes in biodiversity,ecosystem services and agricultural production.In parallel,large-scale abandonment of croplands,especially on sandy,salty or fre-quently inundated areas,became common.Abandoned croplands are usually sensitive to species invasions,and are hotspots of noxious weeds,posing threats both to agriculture and nature conservation.Grassland restoration on former croplands can be an effective strategy for suppressing these species.Thus,a common goal of nature conservation and agriculture can be the restoration of grasslands on former croplands to(1)suppress weed and/or invasive species in line with the EU policy“Good Farming Practices”,(2)support animal husbandry by creating meadows or pastures,and to(3)recover biodiversity and ecosystem services.In the present paper we report“best practices”of grassland restoration projects from Hungary.Our aim was to compare the effectiveness of spontaneous grassland recovery vs.active grassland restoration by seed sowing in terms of the recovery of biodiversity and ecosystem services,such as weed control and biomass production.Our results showed that grassland restoration on abandoned fields offers a viable solution for restoring biodiversity and ecosystem services.Seed sowing ensures higher weed control and biomass pro-duction,but results in lower biodiversity compared to spontaneous recovery.Both restoration methods can be cost-effective,or even profitable even within a relatively short period of a nature conservation project.

Agricultural land use intensity study in Taibus Banner, and its determinants： a case Inner Mongolia, China

Based on rural household survey data from Taibus Banner, in the Inner Mongolia Autonomous Region, China, this study separately categorizes agricul- tural land use intensity into labor intensity, capital intensity, the intensity of labor-saving inputs, and the intensity of yield-increasing inputs, and then analyzes their determinants at the household level. The findings reveal that within the study area： （1） labor intensity is higher and capital intensity is lower than in the major grain-producing and economically developed areas of eastern and central China; （2） the most widely planted crops are those with the lowest labor intensity （oats） and capital intensity （benne）; （3） there are marked differences in agricultural land use intensity among households; a major factor affecting land use decision-making is the reduced need for labor intensity for those households with high opportunity costs, such as those with income earned from non-farming activities which alleviates financial constraints and allows for increased capital intensity. As a result, these households invest more in labor-saving inputs; （4） households with a larger number of workers will allocate adequate time to manage their land and thus they will not necessarily invest more in labor-saving inputs. Those households with more land to manage tend to adopt an extensive cultivation strategy. Total income has a positive impact on capital intensity and a negative impact on labor intensity. House- holds that derive a higher proportion of their total income through farming are more reliant upon agriculture, which necessitates significant labor and yield-increasing inputs. Finally, the authors contend that policy makers should clearly recognize the impacts of non-farming employment on agricultural land use intensity. In order to ensure long- term food security and sustainable agricultural develop-ment in China, income streams from both farming and non- farming employment should be balanced.