Search

The study of soil microbial biomass and enzymatic activity of natural and anthropogenically transformed ecosystems was carried out. The catenas of virgin luvisols and chernozems of the Belogorye Natural Reserve and the catenas of arable soils were studied under similar geomorphological and lithological conditions. The activities of enzymes involved in the cycles of carbon (β-glucosidase and xylosidase), nitrogen (chitinase), and phosphorus (acid and alkaline phosphatase) was studied. It has been established that a decrease in soil microbial biomass as a result of plowing is not accompanied by an equivalent decrease in the enzymatic activity of the soil. Differences in the enzymatic activity of different soils types were revealed, which indicates differences in the structure of the microbial community and the type of phytocenoses. Patterns of changes in the enzymatic activity of soils in watershed areas, in the transit and accumulative parts of catenas, have been established. The values of specific activities of enzymes (enzymatic activities per unit of microbial biomass) were calculated. The obtained patterns of changes in the specific enzymatic activity of arable soils indicate that, despite the loss of organic matter and a decrease in microbial biomass as a result of plowing, the physiological efficiency of the microbial community of agrochernozem is higher than in virgin soil. High specific enzymatic activity in arable soils is associated with higher rate of enzyme production by soil microorganisms due to land use changes. [ABSTRACT FROM AUTHOR]

While intensive peach production has expanded rapidly in recent years, few studies have explored the environmental impacts associated with specific regional systems or the optimal management strategies to minimize associated environmental risks. Here, data from a survey of 290 native farmers were used to conduct a life cycle assessment to quantify the acidification potential (AP), global warming potential (GWP), eutrophication potential (EP), and reactive nitrogen (Nr) losses in peach production in Pinggu District, Beijing. Total annual Nr losses, and GWP, AP, and EP values for peach production in Pinggu District were respectively 10.7 kg N t−1, 857 kg CO2-eq t−1, 12.9 kg SO2-eq t−1, and 4.1 kg PO4-eq t−1. The principal driving factors were fertilizer production, transportation, and application, which together accounted for 94%, 67%, 75%, and 94% of Nr losses, GWP, AP, and EP, respectively. In the high yield, high nitrogen-use efficiency (HH) group, relative values of Nr losses, GWP, AP, and EP were respectively 33%, 25%, 39%, and 32% lower than the overall averages for 290 orchards. Further analyses indicate that improved farming practices such as decreasing application rates of fertilizers, increasing proportion of base fertilization rate, and proper fertilization frequency in the HH group were the main reasons for these orchards' better performance in peach yields and partial factor productivity of nitrogen fertilizer, and their reduced environmental impacts. These results highlight the need to optimize nutrient management in peach production in order simultaneously to realize both environmental sustainability and high productivity in the peach production system. [ABSTRACT FROM AUTHOR]

Water shortage is a serious threat to agriculture production in the North China Plain. Sustainable management practices can improve the water use efficiency of winter wheat, but currently no academic consensus has been reached. Therefore, we performed a meta-analysis that included 2194 observations from 209 articles to assess the water use efficiency of wheat in this area. The groundwater provides for 34%–37% of wheat evapotranspiration, which increases the decline of groundwater levels. The management of wheat irrigation appears to be the key process in improving agricultural water use efficiency. We observed from regression analyses that the factors such as climate, soil, and management significantly affect the water use efficiency of wheat (p < 0.05). The data showed that nitrogen input and irrigation significantly increased wheat yields (p < 0.05), but irrigation did not significantly improve the water use efficiency compared to rain-fed wheat. The optimal water use efficiency was obtained when the irrigation amount was 80–160 mm, or irrigation was applied twice, or the seasonal irrigation amount plus precipitation was ≤ 240 mm. In contrast, a nitrogen input significantly increased evapotranspiration and water use efficiency. The water use efficiency improvement was especially prominent when the nitrogen application rate was 220–250 kg·ha−1. Moreover, subsoiling and straw return should be recommended for increasing yield, reducing evapotranspiration, and improving water use efficiency. These practices can ultimately save over 240 mm of water and 75 kg·ha−1 of nitrogen, which contributes to a sustainable agricultural development. Here, we demonstrate for the first time the impact of management practices on crop water use efficiency at a regional scale and propose a sustainable agricultural development scheme. [ABSTRACT FROM AUTHOR]

The productivist model implemented after the second world war has succeeded in improving production to meet growing demands for food, but it has also deeply affected soil physicochemical properties, as well as of aboveground and belowground biodiversity. Alternative farming systems such as organic farming, biodynamic farming and soil conservation farming are actually developing to enhance the sustainability of farming systems. Although the impact of agricultural practices on soil ecological quality is well known, there is little knowledge on the impact of the different farming systems as a whole. Here, we analysed the impact of the main farming systems on soil biodiversity and functioning, reported in about 100 scientific publications. We found that conventional, organic, and biodynamic systems are the most widely studied, whereas soil conservation farming is poorly documented. Soil biological indicators are improved by ca. 70% in organic farming and biodynamic farming relative to conventional farming. 43% of soil bioindicators are improved in biodynamic farming relatively to organic farming. Soil conservation farming scores better than conventional farming for 57% of the indicators. Therefore, biodynamic farming displays the highest soil ecological quality, followed by organic farming, soil conservation farming and, last, conventional farming. Organic fertilisation and longer crop rotations are the most favourable practices, whereas pesticides and soil tillage are the most deleterious ones. The review also evidences a lack of studies on soil conservation farming and on bioindicators of the soil fauna. [ABSTRACT FROM AUTHOR]

Sugarcane is an important cash crop of Thailand. With a contribution of 5.5% to the total world production, Thailand is the fourth largest producer of sugarcane next to Brazil, India, and China. During the crop year 2014/15, about 103.7 million tonnes of cane was produced with a national average of about 76.6 tonnes/ha, higher than the world average of 69.5 tonnes/ha and also of those countries ranking higher in terms of total production. The major sugar-producing regions of Thailand are northeastern, central, and northern parts, for which the share of production was 44.59, 28.98, and 26.43%, respectively, in crop year 2016/17. Sugarcane is labor intensive for almost all operations, from land preparation to harvesting. Machinery can help in labor saving and timeliness of operations, improving quality of work, reducing drudgery and operation cost, and more importantly, increasing effective utilization of resources. Sugarcane growers are facing serious problems such as labor shortage and high minimum wage for manual labor. Sometimes, mishandling of a problem may result in other serious consequences. For instance, burning sugarcane to reduce labor requirement in harvesting may lead to other problems. Mechanization can play a vital role in solving problems and in improving efficiency of the present sugarcane production system. This paper presents the progress of farm mechanization in sugarcane cultivation in Thailand through on overview of the machinery used in different farm operations based on farming practices as well as their impact and also factors influencing the extent of mechanization in this crop. Future prospects of mechanization are also discussed. [ABSTRACT FROM AUTHOR]

Results of a survey of 156 Chinese mitten crab ( Eriocheir sinensis) grow-out farms around Hongze Lake (118.48-118.72°E; 33.36-33.38°N) are reported. Area farmed has remained relatively unchanged but production (59 932 t in 2012) increased steadily over the last 7 years, indicative of the viability and sustainability of the farming system that has gradually replaced intensive Chinese major carp polyculture around Hongze Lake. Results showed that production range was 135-2400 kg ha cycle (mean 1144 ± 34). Crab yields correlated linearly to stocking density and conformed to a normal distribution curve, with 66.7 % of farms yielding 900 kg ha cycle or more. Yield was negatively correlated to pond size and capture size ( p < 0.01), and farms with macrophyte coverage rate lower than 30 % of water surface were significantly ( p < 0.05) lower than those exceeding 30 %. [ABSTRACT FROM AUTHOR]

There is ample evidence to suggest that liming can regulate soil organic carbon (SOC) pools either directly through influencing the solubility of SOC or indirectly by altering total organic C input as crop residue and SOC loss via change in microbial activity. The aim of this study was to determine the long-term impact of lime application on the quantity and quality of SOC in acid soils. Soils were collected at depths of 0-10, 10-20, 20-30, 30-40, and 40-50 cm from four long-term lime trials with various lime rates (0-25 t ha), lime histories (5-35 years), and soil textures (clay content 5-36 %). Surface application of lime was effective in ameliorating both topsoil and subsoil acidities at sites with low clay content. Liming decreased dissolved organic C (DOC) at 0-30 cm but increased its aromaticity. Total SOC at 0-10 cm decreased or remained unchanged following long-term liming, depending on the rates of lime application and crop management. Changes in the contents of particulate organic C (POC) and humic organic C (HOC) predicted by mid-infrared spectroscopy (MIR) and partial least squares regression (PLSR) showed a similar trend to total SOC at all sites. Lime application had no significant effect on SOC below 10-cm layers and on the MIR-predicted resistant organic C (ROC) fraction. Solid-state C nuclear magnetic resonance (NMR) spectra indicated that the alkyl C content and alkyl/O-alkyl C ratio were lower in the limed than unlimed plots. Liming possibly had a marked effect on regulating the decomposition and preservation of certain C compounds. The apparent accumulation of alkyl C in the unlimed soil could indicate the potential ability of acid soils to store SOC. [ABSTRACT FROM AUTHOR]

Part II. Focuses on the potential effect of farming and agricultural practice on dinitrogen oxide emission from subtropical agricultural soils in Guizhou Province, China. Use of a corn-rape rotation and a soybean-winter wheat rotation field in Guizhou Province; Influence of fertilizer types on dinitrogen oxide; Conclusion.

China is a country with a long history of civilization. Its civilization centers re-located from the plains of the lower and middle reaches of the Yellow River to the basin of the lower watershed of the Yangtze River. This paper analyzes the ecological environmental background of the changes of the civilization centers established in the main dynasties and regimes in ancient China, in which the dynamics of population, farmland, forest, and natural disasters for each period are emphasized. The relationship between environmental degradation, wars, and social development cycles, are also discussed. The results show that anthropogenic environmental impact was one of the decisive contributing factors leading to the relocation of the centers of civilization in ancient China. It is suggested that the rise and fall of ancient civilizations in China and other countries provide modern societies withimportant lessons for environmental protection. [ABSTRACT FROM AUTHOR]