Evaluation of Trace Elements in the Soil of Typical Peach Orchards in Zunyi City

[Objectives]This study was conducted to clarify the enrichment and paucity of trace elements in the soil environment of peach orchards in Zunyi City,and to provide reference for supplementary application of microelement fertilizers and high-quality peach production in peach orchards.[Methods]Taking the soil of three typical peach orchards(Taoli Renjia peach orchard,Pengrui peach orchard and Taohuadao peach orchard)in Shenxi Town,Honghuagang District,Zunyi City as the research object,the contents of trace elements in soil were analyzed through field sampling and indoor determination of trace elements.[Results]The effective contents of trace elements in the soil of peach orchard bases in the study area were at a medium level,and the soil of the peach orchards was rich in available Fe and Se.The contents of available Cu,Mo and Mn were relatively rich.The contents of available B were not high overall.The contents of available Zn were at a moderate to low level overall.The soil of Taoli Renjia peach orchard was relatively rich in trace elements.[Conclusions]The research results can provide a scientific basis for the production of high-quality crispy peaches in peach orchards.

Tree-Temperature Monitoring for Frost Protection of Orchards in Semi-Arid Regions Using Sprinkler Irrigation

Automated over-tree sprinkler irrigation systems were developed and tested in two orchards located in two separate locations in southern Iran （a 0.17 ha peach orchard and a 0.24 ha orange orchard） to protect peach blossoms and orange trees leaves and fruits from low temperature damage. The experiment used a system that monitored the trees and air temperatures using two thermistors. The water application rate by the irrigation system was determined by an energy balance as implemented by the software FROSTPRO, In the peach orchard, the system was tested during three frost events during the spring of 2003 and three other events during the spring of 2004. The system successfully kept peach flowers above the critical temperature, i.e., -4.0℃ in spring 2004 （control block -4.12℃, and sprinkled block ＋0.5℃） during all events. Similar results were obtained in the orange orchard during three frost events in the winter of 2004, during which the tree temperatures were at least 2.5℃ above the critical temperature. Results from field tests show that the system can effectively protect the peach blossoms from damage. Determination done after the frost events showed a 12% blossom kill in the sprinkled blocks while in the unsprinkled control block a 41.5% blossom kill. Calculations indicated that when using variable application rates, the amount of water used can be reduced by 54.3%. Spatial distribution of minimum temperatures during the three frosts was also studied in Jahrom, Iran. Results showed a significant temperature control in the experimental block, especially in the central part of the orchard, but the block margins （about 3.6% of the total area） were at the risk of low temperature due to the wind drift effects.

Scheme of Weather-Based Indemnity Indices for Insuring Against Freeze Damage to Citrus Orchards in Zhejiang,China

We design a weather-based indemnity index for the insurance against freeze damage to citrus orchards so as to provide technological support for the development of policy-based agriculture. The indices are prepared by separating a relative meteorological yield from the yield that is dependent on tree age, high-yield and low-yield years, and environmental factors, and then using a risk assessment scheme to determine the percentage yield reduction due to the meteorological hazard. We thus develop a set of indices associated with cold temperature damage with which to construct more severe weather indices in conjunction with the yield percentage decrease. We then combine the insured regional citrus yield index with the insured meteorological counterpart to obtain a weather-based indemnity index for the varying degree of freeze damage to crops. When the freeze damage index （FDI） is greater than -7.0℃ for the coastal belt of Zhejiang Province, China, or greater than -9.0℃ for other regions of Zhejiang, weather-based indemnity index （WBII） is zero, meaning there is no compensation; when the FDI is from -7.0 to -7.9℃ for the coastal belt or from -9.0 to -9.9℃ for other regions, the WBII is 1 with 50% compensation; when the FDI is from -8.0 to -8.9℃ for the coastal belt or from -10.0 to -10.9℃ for other regions, the WBII is 2 with 70% compensation; and when the FDI is less than -9.0℃ for the coastal belt or less than -11.0℃ for other regions, the WBII is 3 with 90% compensation. The weather indemnity indices of insured orchards are developed in the interest of owners, thereby eliminating adverse selection and moral hazard issues and providing timely recompense from the insurer, and resolving the problem of high indemnity cost in agricultural insurance.

Reducing nitrogen fertilization of intensive kiwifruit orchards decreases nitrate accumulation in soil without compromising crop production

Excessive nitrogen （N） fertilization of high value horticultural crops is a common problem that not only increases the cost to farmers, but also negatively affects crop growth and the environment. A three-year field experiment was conducted in an intensive kiwifruit orchard in Shaanxi Province, China to compare the effects of reduced N fertilization applied as urea （U）, and controlled release urea （CRU） on the N nutrition of kiwi vines, fruit yield and quality, and nitrate-N accumulation in the soil profile. The three treatments included a conventional N application rate （CF-U, 900 kg N ha-1 yr-1 as urea）, two reduced N fertilization treatments where the amount of N fertilizer applied as U and CRU was reduced by 25％ in 2013 and 2014, and by 45％ in 2015. The 25 and 45％ reduced N treatments had no adverse effects on the N concentrations in leaves and pruning branches and the fruit yield and quality of kiwi vines. However, they significantly enhanced the partial factor productivity of applied N （PFPN） and the economic benefits, and reduced nitrate accumulation in the 0-200 cm soil profile. The same benefits of reduced N fertilization were observed for both the U and CRU treatments, but the CRU treatment had the added benefit of decreasing the loss of nitrate through leaching. We concluded that the current level of N fertilization in kiwi orchards is very excessive, and reducing the N fertilizer rate by 25-45％ could not only guarantee fruit yield, but also reduce N accumulation and loss.

Characteristics of Soil Organic Carbon, Total Nitrogen, and C/N Ratio in Chinese Apple Orchards

Soil organic carbon and nitrogen are used as indexes of soil quality assessment and sustainable land use management. At the same time, soil C/N ratio is a sensitive indicator of soil quality and for assessing the carbon and nitrogen nutrition balance of soils. We studied the characteristics of soil organic carbon and total nitrogen by investigating a large number of apple orchards in major apple production areas in China. High apple orchard soil organic carbon content was observed in the provinces of Heilongjiang, Xinjiang, and Yunnan, whereas low content was found in the provinces of Shandong, Henan, Hebei, and Shaanxi, with the values ranging between 6.44 and 7.76 g·kg-1. Similar to soil organic carbon, soil total nitrogen content also exhibited obvious differences in the 12 major apple producing provinces. Shandong apple orchard soil had the highest total nitrogen content (1.26 g·kg-1), followed by Beijing (1.23 g·kg-1). No significant difference was noted between these two regions, but their total nitrogen content was significantly higher than the other nine provinces, excluding Yunnan. The soil total nitrogen content for Xinjiang, Heilongjiang, Hebei, Henan, and Gansu was between 0.87 and 1.03 g·kg-1, which was significantly lower than that in Shandong and Beijing, but significantly higher than that in Liaoning, Shanxi, and Shaanxi. Six provinces exhibited apple orchard soil C/N ratio higher than 10, including Heilongjiang (15.42), Xinjiang (13.38), Ningxia (14.45), Liaoning (12.24), Yunnan (11.03), and Gansu (10.63). The soil C/N ratio was below 10 in the remaining six provinces, in which the highest was found in Shaanxi (9.47), followed by Beijing (8.98), Henan (7.99), and Shanxi (7.62), and the lowest was found in Hebei (6.80) and Shandong (6.05). Therefore, the improvement of soil organic carbon should be given more attention to increase the steady growth of soil C/N ratio.

Effects of Farmyard Manure and Inorganic Fertilizer Application on Soil Physico-Chemical Properties and Nutrient Balance in Rain-Fed Lowland Rice Ecosystem

A field experiment was conducted to assess the effects of combined application of farm yard manure (FYM) and inorganic NP fertilizers on soil physico-chemical properties and nutrient balance in a rain-fed lowland rice production system in Fogera plain, northwestern Ethiopia. The study was carried out during the main cropping seasons of 2010 and 2011. Twenty-seven treatments comprising a factorial combination of three rates of FYM (0, 7.5, and 15 t·ha-1), three rates of nitrogen (0, 60, 120 kg·N·ha-1) and three rates of phosphorus (0, 50 and 100 kg·P2O5·ha-1) were tested. The experiments were laid out as a randomized complete block design with three replications. Bulk density, organic matter content, and available water holding capacity, total N, and available P of the soil were measured just after harvesting the rice crop. Results showed that application of 15 t·FYM·ha-1 significantly increased soil organic matter and available water holding capacity but decreased the soil bulk density, creating a good soil condition for enhanced growth of the rice crop. Application of 15 tFYM·ha-1 increased the level of soil total nitrogen from 0.203% to 0.349%. Combined application of 15 t·ha-1·FYM and 100 kg·P2O5·ha-1 increased the available phosphorous from 11.9 ppm to 38.1 ppm. Positive balances of soil N and P resulted from combined application of FYM and inorganic N and P sources. Application of 15·t ha-1·FYM and 120 kg·N·ha-1resulted in 214.8 kg·ha-1·N positive balance while application of 15 t·ha-1·FYM and 100 kg·P2O5·ha-1 resulted in a positive balance of 69.3 kg·P2O5·ha-1 available P. From the results of this experiment, it could be concluded that combined application of FYM and inorganic N and P fertilizers improved the chemical and physical properties, which may lead to enhanced and sustainable production of rice in the study area.

Seasonal and Annual Variations of CO_2 Fluxes in Rain-Fed Winter Wheat Agro-Ecosystem of Loess Plateau, China

To accurately evaluate the carbon sequestration potential and better elucidate the relationship between the carbon cycle and regional climate change, using eddy covariance system, we conducted a long-term measurement of CO 2 fluxes in the rain-fed winter wheat field of the Chinese Loess Plateau. The results showed that the annual net ecosystem CO 2 exchange （NEE） was （-71.6±5.7） and （-65.3±5.3） g C m-2 y-1 for 2008-2009 and 2009-2010 crop years, respectively, suggesting that the agro-ecosystem was a carbon sink （117.4-126.2 g C m-2 yr-1）. However, after considering the harvested grain, the agro- ecosystem turned into a moderate carbon source. The variations in NEE and ecosystem respiration （R eco ） were sensitive to changes in soil water content （SWC）. When SWC ranged form 0.15 to 0.21 m3 m-3, we found a highly significant relationship between NEE and photosynthetically active radiation （PAR）, and a highly significant relationship between R eco and soil temperature （T s ）. However, the highly significant relationships were not observed when SWC was outside the range of 0.15-0.21 m3 m-3. Further, in spring, the R eco instantly responded to a rapid increase in SWC after effective rainfall events, which could induce 2 to 4-fold increase in daily R eco , whereas the R eco was also inhibited by heavy summer rainfall when soils were saturated. Accumulated R eco in summer fallow period decreased carbon fixed in growing season by 16- 25%, indicating that the period imposed negative impacts on annual carbon sequestration.

Water use efficiencies of maize cultivars grown under rain-fed conditions

Enhancing water use efficiencies of rain-fed maize is a requirement for sustainable maize production, particularly in areas prone to low/drought and erratic rainfall patterns. This study was conducted to assess the relationship between total biomass/grain yield and water use efficiencies of three maize cultivars (Golden Crystal, Mamaba and Obatanpa) grown under rain-fed conditions in a coastal savannah agro-ecological environment of Ghana. Results of the study showed that a unified linear model, WUETDM = 0.03TDM with R2 = 0.765 and P ≤ 0.001, described adequately the relation between wa-ter use efficiency and total biomass (dry matter), which is applicable for the three maize cultivars for both the major and minor cropping seasons. A linear model could only, however, describe adequately well the relation between WUEGY and GY for the major (WUEGY = 0.001GY – 0.67;R2 = 0.996;P ≤ 0.001) and minor (WUEGY = 0.002GY + 0.289;R2 = 0.992;P ≤ 0.001) cropping seasons for all the maize cultivars. The linear models developed for the maize cultivars, re-lating WUEGY to GY, are specific to each of the crop growing seasons, indicating that seasonal rainfall impacts significantly on harvest index of the maize cultivars but differently in each of the crop growing seasons as a results of dif-ferences in seasonal rainfall. However, the models could be used to estimate water use efficiencies of each of the three maize cultivars given the appropriate TDM and GY as inputs for the environment under which the study was conducted.

Resilience, reliability and risk analyses of maize, sorghum and sunflower in rain-fed systems using a soil moisture modeling approach

This paper is aimed at examining the applicability of methods for resilience, reliability and risk analyses of rain-fed agricultural systems from modeled continuous soil moisture availability in rain-fed crop lands. The methodology involves integration of soil and climatic data in a simple soil moisture accounting model to assess soil moisture availability, and a risk used as indicator of sustainability of rain-fed agricultural systems. It is also attempted to demonstrate the role of soil moisture modeling in risk analysis and agricultural water management in a semi-arid region in Limpopo Basin where rain-fed agriculture is practiced. For this purpose, a daily-time step soil moisture accounting model is employed to simulate daily soil moisture, evaporation, surface runoff, and deep percolation using 40 years (1961-2000) of agroclimatic data, and cropping cycle data of maize, sorghum and sunflower. Using a sustainability criterion on crop water requirement and soil moisture availability, we determined resilience, risk and reliability as a quantitative measure of sustainability of rain-fed agriculture of these three crops. These soil moisture simulations and the sustainability criteria revealed further confirmation of the relative sensitivity to drought of these crops. Generally it is found that the risk of failure is relatively low for sorghum and relatively high for maize and sunflower in the two sites with some differences of severity of failure owing to the slightly different agroclimatic settings.

Highly-efficient Stereo-cultivation Model in Kiwifruit Orchards Interplanting Konjak

The kiwifruit orchards with plants growing for over two years were chosen for interplanting of konjak, which takes advantages of complementation of the two plants in terms of habits, reducing water and soil erosions effectively, and decreasing water evaporation, and konjak diseases. Furthermore, the interplanting doubles planting benefits and constitutes a highly-efficient planting model.

Status of Soil Nutrients in Citrus Orchards of Guangxi

Based on the investigation of 56 soil samples( 0-30 cm) in citrus orchards of Guangxi,the content of soil organic matter and available nutrients as well as their correlations in the citrus orchards were studied. The results showed that soil was rich in organic matter,and the proportion of soil samples deficient in available N,P and K was 30. 36%,32. 14% and 28. 57% respectively. Soil was seriously deficient in soil available Ca,Mg and B,while the content of soil available Fe and Cu in soil was too high. There were significant or extremely significant positive or negative correlations between soil pH,organic matter and several available nutrients. It is recommended to apply Mg fertilizer,B fertilizer,lime or other alkaline fertilizer and reduce the spraying of fungicides containing Cu in the citrus orchards.

Black locust (Robinia pseudoacada L.) clonal seed orchards in Hungary

Black locust （Robinia pseudoacacia L.） is one of the most important stand-forming tree species in Hungary and its impor- tance is increasing in many countries. The main aim of the discussed new selection programme is to identify black locust clones with good performance and good form for setting up clonal seed orchards. As a result of selection programme 16 new black locust clones have been improved. In spring 2002 a black locust seed orchard was established with the newly selected clones. About 40% of the plants can be considered to belong to the height growth rate class 1 and 2. Hungary was the first country where micropropagated black locust planting material was used for seed orchard establishment.

Chemical properties during different development stages of fruit orchards in the mekong delta (Vietnam)

This study to examine soil fertility status was conducted on 10 citrus plantations in Hau Giang province within the Vietnamese Mekong Delta, Vietnam. Fruit trees are mostly grown on the raised beds to avoid annual flood with alluvial soil type. Soil sampling was done in the dry season of 2010 at two soil depths, for each raised bed. Development ages of raised beds were represented by two groups, young age group (≤ 30 years) and old age group (> 30 years). For chemical analysis, pH, organic matter, CEC, total nitrogen, NH4+, NO3– and exchangeable Ca, Mg and K were determined. The results showed that the pH (water) was strongly acid. The CEC was in average 19.2 cmol+.kg–1 in topsoil (0 - 20 cm depth) and 18.7 cmol+.kg–1 in subsoil (20 - 50 cm depth) for young age group. Similarly, the CEC was 16.7 cmol+.kg–1 in topsoil and 15.8 cmol+.kg–1 in subsoil for old age group. Organic matter on young age group (7.38 and 5.47% on average for topsoil and subsoil respectively) was significantly higher than that of old age group (5.20 and 3.81% on average for topsoil and subsoil respectively). Total nitrogen was not significantly different between the sites for the age groups of raised as well as the soil layers. Ammonium-N levels were excessive, and NO3--N levels were high. Potassium and Mg2+ were significantly different between age groups of raised beds and the same pattern between soil layers, while Ca2+ did not vary significantly. Potassium and Ca2+ levels were moderate, Mg2+ was high and P levels were very high. Soil fertility in the raised beds subjected to an adverse on plant growth and an imbalance in soil nutrients under low pH conditions. Loss of soil quality was exhibited in reduced organic matter with the aging of raised beds.

Carbon Budget Dynamics over a Rain-Fed Maize Agricultural Ecosystem in Northeast China and Its Regulation

Based on the eddy-covariance observation data over rain-fed maize agricultural ecosystem during 2005-2011, the dynamics of net ecosystem CO2 exchange (NEE) and its control mechanism were analyzed in the present study. We found that the average carbon budget of non-growing season, growing season and annual were 153.16 - 202.03 g C/m2, −689.36 - −488.17 g C/m2, and −316.96 - −487.33 g C/m2, respectively. Maize carbon content of grain yield was −226.6 - −339.94 g C/m2, accounting for 55.4% of carbon budget in the growing season. From sowing to seven-leaf stage, the carbon budget of this ecosystem was characterized by carbon release, with the rate of 0.028 ±0.0056 mg CO2 m−2⋅s−1. From seven-leaf to mature stage, the carbon budget was characterized by carbon absorption, with the rate of −0.256 ±0.0693 mg CO2 m−2⋅s−1. The key meteorological factors affecting annual carbon budget included daily average temperature (R = −0.81, P = 0.03) and saturated vapor pressure deficit (R = −0.64, P = 0.12). At the same photosynthetically active radiation (PAR) level, CO2 assimilation rate was linearly correlated with leaf area index (P 【0.05), and the slopes increased with PAR, indicating the increase in net ecosystem CO2 exchange in growing season was unlikely to be resulted from the extension of growing season. On the contrary, the carbon sink of rain-fed maize ecosystem in growing season might be decreased by extending the growing season ahead of the sowing date.

Preliminary Study on the Mechanization Demand of Orchards in North China

From the production management practice of fruit trees in North China by agricultural research institutions,combining the relevant national policies and documents in recent years,the demand for orchard machinery in fruit tree production of North China is summarized,and preliminary thoughts and suggestions are put forward.It could promote the joint of machinery and agriculture(industry,university,research and application departments),and improve mechanization level of orchards in North China.

Current Research Situation and Development Countermeasures for Digital Orchards

With the rapid development of modern information technology, digital technology has gradually penetrated into all fields and links of the agricultural industry. Digital orchard reflects the comprehensive application of digital technology in orchard management. This study surveys and analyzes the current development of digital orchard, clarifies the development status and existing problems, and comes up with reasonable recommendations, to provide a certain reference and guidance for the construction of digital orchard in Zibo City of Shandong Province.

Analysis and Forecasting of the Impact of Climatic Parameters on the Yield of Rain-Fed Rice Cultivation in the Office Riz Mopti in Mali

During the period spanning the 1970s and1980s, countries in the West African Sahel experienced severe drought. Its impact on agriculture and ecosystems has highlighted the importance of monitoring the Sahelian rainy season. In Sahelian countries such as Mali, rainfall is the major determinant of crop production. Unfortunately, rainfall is highly variable in time and space. Therefore, this study is conducted to analyze and forecast the impact of climatic parameters on the rain-fed rice yield cultivation in the Office Riz Mopti region. The data were collected from satellite imagery, archived meteorology data, yield and rice characteristics. The study employed Hanning filter to highlight interannual fluctuation, a test of Pettitt and the standardized precipitation index (SPI) to analyze the rainfall variability. Climate change scenarios under the RCP 8.5 scenario (HadGEM-2 ES) and agroclimatic (Cropwat) model are carried out to simulate the future climate and its impact on rice yields. The results of satellite image classifications of 1986 and 2016 show an increase of rice fields with a noticeable decrease of bare soil. The analysis of the SPI reveals that over the 30 years considered, 56.67% of the rainy seasons were dry (1986-2006) and 43.33% were wet (2007-2015). The modelling approach is applied over 1986-2006 and 2007-2015 periods—considered as typical dry and rainy years—and applied over the future, with forecasts of climate change scenarios in 2034. The results show a decrease in potential yield during dry and slightly wet years. The yields of rain-fed rice will be generally low between 2016 and 2027. Deficits are observed over the entire study area, in comparison with the potential yield. Thus, this situation could expose the population to food insecurity.

Hawk‐eye‐inspired perception algorithm of stereo vision for obtaining orchard 3D point cloud navigation map

The binocular stereo vision is the lowest cost sensor for obtaining 3D information.Considering the weakness of long‐distance measurement and stability,the improvement of accuracy and stability of stereo vision is urgently required for application of precision agriculture.To address the challenges of stereo vision long‐distance measurement and stable perception without hardware upgrade,inspired by hawk eyes,higher resolution perception and the adaptive HDR(High Dynamic Range)were introduced in this paper.Simulating the function from physiological structure of‘deep fovea’and‘shallow fovea’of hawk eye,the higher resolution reconstruction method in this paper was aimed at ac-curacy improving.Inspired by adjustment of pupils,the adaptive HDR method was proposed for high dynamic range optimisation and stable perception.In various light conditions,compared with default stereo vision,the accuracy of proposed algorithm was improved by 28.0%evaluated by error ratio,and the stability was improved by 26.56%by disparity accuracy.For fixed distance measurement,the maximum improvement was 78.6%by standard deviation.Based on the hawk‐eye‐inspired perception algorithm,the point cloud of orchard was improved both in quality and quantity.The hawk‐eye‐inspired perception algorithm contributed great advance in binocular 3D point cloud recon-struction in orchard navigation map.

Changes in Soil Moisture Content and Characteristics ofWater Movement in Citrus Orchards under Different Mulching Methods

[Objectives]The paper was to explore the effects of different mulching methods on soil moisture content and water movement in citrus orchards,and to provide the theoretical basis for improving water and weed management level in orchards.[Methods]Three ground mulching treatments including spraying herbicide(CK),grass-proof cloth cover(GPC)and natural grass mowing(NGM)were set up to analyze the soil moisture content and water flux characteristics of soil profile in the soil layers of 5,20,40 and 60 cm under different mulching methods.[Results]The GPC and NGM treatments significantly increased the soil moisture content in the soil layer of 0-60 cm at the young fruit stage and fruit expansion stage,which inhibited soil water evaporation and effectively improved soil water holding capacity,thus reducing irrigation water consumption and saving water resources.During the expansion stage of citrus fruits,the soil water flux in the soil layer of 0-60 cm in NGM and CK treatments was upward,and the upward soil water flux in NGM treatment was larger,which could mobilize more upward movement of deep soil moisture for uptake by citrus roots.However,the soil water flux in the soil layer of 0-60 cm in GPC treatment was downward,and the soil moisture conditions in the upper and middle layers were already sufficient for citrus growth.[Conclusions]Both GPC and NGM treatments can increase the overall soil moisture content.In the dry season,the soil moisture content in the upper layer treated by GPC is always relatively high,while more soil water in the lower layer move to the upper layer in NGM treatment,which has met the water requirements for citrus growth.