Apple Orchard Soil Research Articles

Red clover intercropping of apple orchards improves soil microbial community functional diversity

This study investigated the effects of forage species and sampling depths on microbial community functional diversity in soil collected between rows of apple trees. Apple orchard soils' intercropping of three different forage species, including native wild grasses, red clover (RC), ryegrass, and clean tillage (CT) at varying depths (0–10, 10–20, and 20–30 cm), was analyzed using Biolog Eco-PlateTM. The average well color development (AWCD) in samples subject to ELISA indicated that the carbon metabolic capacities of the microbial community in RC soil were greater than those in the remaining three soil treatments, with no significant (P>0.05) differences among the three depths. Diversity and richness indices of the bulk soil samples (except the RC) declined significantly with depth, while the evenness indices of most soil samples only demonstrated a slight change. The diversity and richness indices of the CT of 0–10-cm soil sample were markedly higher than those of 10–20-cm and 20–30-cm soil samples, especially when compared with the remaining three soil treatments. Principal component (PC) analysis showed that the CT soil at 10–20 and 20–30 cm was oriented in the axis-positive direction of the PC2 axis, but was oriented in the axis-negative direction at 0–10 cm. Therefore, we surmise that there exists an extensive microbial diversity among the soil samples. In summary, our results show that planting RC improved microbial community functional diversity to a greater extent than did the other forage species and CT at all the three measured soil depths, except for CT at a 0–10 cm soil depth.

AMELIORATING EFFECTS OF SOME BASIC AMENDMENTS ON ACIDIFIED SOIL IN APPLE ORCHARDS

Some soil types are becoming acidified because of intensive fertilization and irrigation over the past 20 years of apple (Malus ×domestica) production in Shandong Province, China. Soils prone to acidification usually have less organic matter and lower biological activity, which results in a lower soil sustainable fertility index (SSFI), calculated from soil nutrients, available nutrients, and soil biological activity. Traditionally, lime and limestone are used to raise soil pH, but they are not so effective for improving soil fertility. We tested two alternative acidified soil amelioration materials (ASAM) for increased soil improvement. ASAM1 was made from plant ash, calcium cyanamide, calcium, magnesium, and phosphorous; ASAM2 was comprised of bentonite used to absorb pigment in the soybean oil manufacturing process and grain (cereal) residues from Chinese spirit fermentation as an organic matter base. The effects of ASAM1, ASAM2 and lime were compared for efficacy in increasing soil pH, enzyme activity, SSFI, and number of fungi, bacteria, and actinomycetes in two apple orchard soils where soil pH was below 5.5. Both ASAMs applied in this study significantly improved the indices investigated. ASAM1 application increased pH by 0.50 and 0.46 in the two orchards, respectively, in comparison with the control. However, lime application caused no significant increase in nutrient elements, soil enzyme activity, or SSFI. The results suggest that some new mixtures of soil amendments made from basic materials and agricultural by-products and wastes can be used to improve acidified soils in old apple orchards.

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.

<i>Eustigmaeus nahidae</i>, a new species of the genus <i>Eustigmaeus</i> Berlese (Acari: Stigmaeidae) from northwest Iran

Abstract A new specie of Eustigmaeus, E. nahidae sp. nov. is described based on females and males collected from soil in apple orchards in Bonab, East Azerbajan province, Iran.

A new species and new record of <i>Stigmaeus</i> Koch (Acari: Stigmaeidae) from northwest Iran

A new species of Stigmaeus Koch (Acari: Stigmaeidae), S. haddadi n. sp., is described and illustrated. This species was collected from soil in apple orchards at Miandoab, West Azerbaijan Province, Iran. Stigmaeus pulchellus Kuznetzov is recorded for the first time in Iran, and is redescribed.

Stigmaeus maraghehiensis, a new species of the genus Stigmaeus Koch (Acari: Stigmaeidae) from northwest Iran

A new species of Stigmaeus Koch (Acari: Stigmaeidae), Stigmaeus maraghehiensis sp. nov., is described and illustrated from the soil in apple orchards in Maragheh, East Azerbaijan Province, Iran. A key to all known Iranian species of the genus is provided.

Eustigmaeus setiferus, n. sp. (Acari: Stigmaeidae) from Iran

ABSTRACT A new species of Eustigmaeus Berlese, 1910 (Acari: Stigmaeidae), Eustigmaeus setiferus n. sp., is described and illustrated from soil in apple orchards at Maragheh, East Azerbaijan Province, Iran.

Cheylostigmaeus gharakhanii sp. nov. (Acari: Trombidiformes: Stigmaeidae) from Northwest Iran.

A new species of Cheylostigmaeus Willmann (Acari: Trombidiformes: Stigmaeidae), Cheylostigmaeus gharakhanii sp. nov., is described and illustrated based on females and males. It was collected from soil in apple orchards at Marand, East Azerbaijan province, Iran.

SMB-1, a Novel Subclass B3 Metallo-β-Lactamase, Associated with IS CR1 and a Class 1 Integron, from a Carbapenem-Resistant Serratia marcescens Clinical Isolate

A carbapenem-resistant Serratia marcescens strain, 10mdr148, was identified in a Japanese hospital in 2010. The carbapenem resistance of this strain was attributed to the production of a novel metallo-β-lactamase (MBL), named SMB-1 (Serratia metallo-β-lactamase). SMB-1 possessed a zinc binding motif, H(Q)XHXDH (residues 116 to 121), H196, and H263 and was categorized as a member of subclass B3 MBL. SMB-1 has 75% amino acid identity with the most closely related MBL, AMO1, of uncultured bacterium, recently identified through the metagenomic analysis of apple orchard soil. The introduction of bla(SMB-1) into Escherichia coli conferred resistance to a variety of β-lactam antibiotics, penicillins, cephalosporins, and carbapenems, but not aztreonam, a resistance pattern consistent with those of other MBLs. SMB-1 demonstrated high k(cat) values of >500 s(-1) for carbapenems, resulting in the highest hydrolyzing efficiency (k(cat)/K(m)) among the agents tested. The hydrolyzing activity of SMB-1 was well inhibited by chelating agents. The bla(SMB-1) gene was located on the chromosome of S. marcescens strain 10mdr148 and at the 3' end of the ISCR1 element in complex with a typical class 1 integron carrying aac(6')-Ib and catB3 gene cassettes. Downstream of bla(SMB-1), the second copy of the 3'conserved segment and ISCR1 were found. To our knowledge, this is the first subclass B3 MBL gene associated with an ISCR1 element identified in an Enterobacteriaceae clinical isolate. A variety of antibiotic resistance genes embedded with ISCR1 have been widely spread among Enterobacteriaceae clinical isolates, thus the further dissemination of bla(SMB-1) mediated by ISCR1 transposition activity may become a future concern.

Description of a new species of the genus <em>Stigmaeus</em> Koch (Acari: Prostigmata: Stigmaeidae) from East Azerbaijan Province, Iran

A new species of Stigmaeus Koch (Acari: Stigmaeidae), Stigmaeus marandiensis sp. nov. is described and illustrated from soil in apple orchards at Marand, East Azerbaijan Province, Iran. A key to all known species from Iran of the genus Stigmaeus is also provided.

Evaluation on Arsenic and Heavy Metal Pollution in Apple Orchard Soil in Shaanxi Province

Arsenic and heavy metal pollution in apple orchard soi1 in Shaanxi Province is evaluated on the basis of geo-accumulation index and ecological risk.Hg pollution is classified as the slight level and moderate level,and there is no pollution of Cd,Cr,Pb,Cu and As according to Igeo based on the background value of arsenic and heavy metals in loess.The pollution frequencies of both Hg and As were 46.8%,they were the highest among the 6 elements,and that of Cd and Cu were 27.4% and 4.8% respectively.The orchard soil was not polluted by Pb and Cr.In the view of the potential ecological risk index,Hg pollution caused the severest hazard,and then by Cd.The remained 4 elements had a slight hazardousness with Eir being less than 20.RI analysis shows that 27.42% of the orchard soil was slightly hazardous,56.45% moderately hazardous,and 16.13% heavily hazardous.

Nitrous oxide emissions from an apple orchard soil in the semiarid Loess Plateau of China

Nitrous oxide (N2O) fluxes from an apple orchard soil in the semiarid Loess Plateau of China were measured using static chambers from September 2007 to September 2008. In this study, three sites were selected at distance of 2.5 m (D 2.5), 1.5 m (D 1.5), and 0.5 m (D 0.5) from the apple tree row. Nitrous oxide fluxes followed seasonal pattern, with high N2O emission rates occurring in the hot-humid summer and low rates in the cold-dry winter. Pulses of N2O emissions occurred after nitrogen fertilizer application, summer rainfall events, and during freeze-thaw cycles. Annual average N2O emission rates were the highest at D 0.5 site (48.2 ± 39.9 µg N2O m−2 h−1), the lowest at D 2.5 site (31.9 ± 18.2 µg N2O m−2 h−1), and intermediate at D1.5 site (36.8 ± 32.2 µg N2O m−2 h−1), suggesting that N2O emissions from the apple orchard soil increased when the chamber location was closer to the apple tree row. This may be due to the fertilization close to roots in hot and humid season. Over one third (37.1%) of the annual N2O emission occurred in the summer. Annual N2O emissions from the apple orchard soil averaged to 3.22 kg N2O ha−1 year−1. Annual emission factor of the apple orchard from the applied fertilizer (uncorrected for background emission) was 0.658%. This value was nearly a half (53%) of the default value provided by the Intergovernmental Panel on Climate Change for the application of synthetic fertilizers to cropland (1.25%). Therefore, the amount of N2O emissions from the semiarid apple orchard soil could be largely overestimated if no regional-specific factor is used.

Microbial and enzyme properties of apple orchard soil as affected by long-term application of copper fungicide

Copper-based fungicides have been applied in apple orchards for a long time, which has resulted in increasing soil Cu concentration. However, the microbial and enzyme properties of the orchard soils remain poorly understood. This study aimed to evaluate the effect of long-term application of Cu-based fungicides on soil microbial (microbial biomass carbon (C mic), C mineralization, and specific respiration rate) and enzyme (urease, acid phosphatase, and invertase activities) properties in apple orchards. Soil samples studied were collected from apple orchards 5, 15, 20, 30, and 45 years old, and one adjacent forest soil as for reference. The mean Cu concentrations of orchard soils significantly increased with increasing orchard ages ranging from 21.8 to 141 mg kg −1, and the CaCl 2-extractable soil Cu concentrations varied from 0.00 to 4.26 mg kg −1. The soil mean C mic values varied from 43.6 to 116 mg kg −1 in the orchard soils, and were lower than the value of the reference soil (144 mg kg −1). The ratio of soil C mic to total organic C (C org) increased from 8.10 to 18.3 mg C mic g −1 C org with decreasing orchard ages, and was 26.1 mg C mic g −1 C org for the reference soil. A significant correlation was observed between total- or CaCl 2-extractable soil Cu and soil C mic or C mic/C org, suggesting that the soil Cu was responsible for the significant reductions in C mic and C mic/C org. The three enzyme activity assays also showed the similar phenomena, and declined with the increasing orchard ages. The mean soil C mineralization rates were elevated from 110 to 150 mg CO 2–C kg −1 soil d −1 compared with the reference soil (80 mg CO 2–C kg −1 soil d −1), and the mean specific respiration rate of the reference soil (0.63 mg CO 2–C mg −1 biomass C d −1) was significantly smaller than the orchard soils from 1.19 to 3.55 mg CO 2–C mg −1 biomass C d −1. The soil C mineralization rate and the specific respiration rate can be well explained by the CaCl 2-extractable soil Cu. Thus, the long-term application of copper-based fungicides has shown adverse effects on soil microbial and enzyme properties.

Seasonal Dynamics of Nitrogen, Phosphorus, and Potassium Contents of Leaf and Soil in Environmental Friendly Apple Orchards

Nowadays, there is increasing interest in environmentally friendly growing systems, and attention has also been paid to the environmental impacts of natural and artificial fertilizations. However, seasonal dynamics of macronutrient status needs further investigations in environmentally friendly apple orchards. Therefore, this study was aimed to determine nitrogen, phosphorus, and potassium contents of leaves in every month during the season and of soil in April and October at Debrecen‐Pallag, Hungary, from 2002 to 2004. The study was performed in integrated and organic apple orchards on three apple cultivars (Mutsu, Elstar, and Reka). All easily soluble (0.01 M CaCl2) and plant‐available nitrogen fractions (nitrate nitrogen, ammonium nitrogen, and total soluble nitrogen) in the soil were significantly higher (P = 0.05) in the integrated apple orchard compared to the organic one. The 0.01 M calcium chloride (CaCl2) soluble ortho‐phosphate and total phosphate fractions of the soil were significantly higher (P = 0.05), whereas organic phosphate and soil pH showed no significant difference in the integrated apple orchard compared to the organic one. Potassium contents of the integrated soils were significantly higher (P = 0.05) compared to those of the organic one. Nitrogen, phosphorus, and potassium contents of leaves were higher in the integrated orchard compared to the organic one. The dynamics of P uptake corresponded to the phenological phases of apple. Potassium content of apple leaves decreased continuously until July, after that it slightly increased, and then it decreased again. In conclusion, results suggest that better mobility of artificial fertilizers in integrated orchards provided higher macronutrient uptake than in organic orchards, where only natural nutrient sources are allowed.

Abstracts of Nippon Dojo-Hiryogaku Zasshi

Abstracts of Nippon Dojo-Hiryogaku Zasshi

An investigation of inorganic antimony species and antimony associated with soil humic acid molar mass fractions in contaminated soils

The presence of antimony compounds is often suspected in the soil of apple orchards contaminated with lead arsenate pesticide and in the soil of shooting ranges. Nitric acid (1 M) extractable Sb from the shooting range (8300 μg kg −1) and the apple orchard (69 μg kg −1) had considerably higher surface Sb levels than the control site (<1.5 μg kg −1), and Sb was confined to the top ∼30 cm soil layer. Sb(V) was the principal species in the shooting range and the apple orchard surface soils. Size exclusion chromatography–inductively coupled plasma-mass spectrometry (SEC–ICP-MS) analysis of humic acids isolated from the two contaminated soils demonstrated that Sb has complexed to humic acid molar mass fractions. The results also indicate that humic acids have the ability to arrest the mobility of Sb through soils and would be beneficial in converting Sb(III) to a less toxic species, Sb(V), in contaminated areas.

Copper Accumulation and Chemical Forms in Bordeaux Mixture Spraying Apple Orchard Soils

Copper Accumulation and Chemical Forms in Bordeaux Mixture Spraying Apple Orchard Soils

Study on the micronutrient content of soil and leaf of an organic apple orchard in Eastern Hungary

The aim of our study was to investigate the relationship between micronutrient content of soil and leaf in an organic apple orchard. The experiment was carried out at the Experimental Site of the University of Debrecen, Centre of Agricultural Sciences at Pallag in an apple cultivar collection in Eastern Hungary in 2002-2004. The soil sampling was carried out twice per year, at the beginning and the end of the vegetation period in 2002, 2003 and 2004, respectively. The micronutrient content of leaf of seven apple cultivars (Jonagold, Mutsu, Idared, Red Elstar, Egri piros, Reka, Remo) was studied according to phenological phases of apple (April — September) to investigate the dynamism of plant nutrient uptake.&#x0D; It was found that results of leaf analysis correlated with the obtained results of soil. According to the data of July, manganese and copper content of leaf is in the 'favourable' but zinc is the 'low' range of nutrient supply category. Moreover, there were significant differences in the micronutrient content of leaf among cultivars. From our results it is evident that more reliable data were obtained for fruit nutrition by determining of micronutrient content of soil and plant and calculate their ratios as well.

Modification of fluorescent pseudomonad community and control of apple replant disease induced in a wheat cultivar-specific manner

Apple orchard soils were cropped for three successive 28-day growth cycles with a perennial ryegrass/annual ryegrass mixture or 1 of 11 wheat cultivars prior to planting with Gala apple seedlings. Prior cropping of soils with ryegrass had no significant impact on growth of apple, but cultivation with some, but not all, wheat cultivars substantially enhanced apple seedling growth. Enhanced growth of apple was associated with a reduction in root infection by the dominant fungal pathogens resident to the respective orchard soils. Wheat cultivars that enhanced growth of apple modified the genetic and species composition of the fluorescent pseudomonad population resident to orchard soil. The fluorescent pseudomonad population from soils cropped with wheat cultivars that enhanced apple seedling growth possessed a higher capacity to inhibit in vitro growth of multiple elements of the fungal complex that incites apple replant disease than did the population from non-treated orchard soil or soil cropped with a wheat cultivar that did not enhance growth of apple. Application of wheat root exudates to soil also modified the antagonistic potential and composition of the fluorescent pseudomonad population in a cultivar-specific manner. This study demonstrates the significant role of plant genotype in determining composition of the saprophytic soil microbial community. It also establishes the need to consider not only plant species but also plant genotype when evaluating the potential benefit of specific cover crops as a component within a systems approach for the management of soilborne plant diseases.

Wheat Genotype-Specific Induction of Soil Microbial Communities Suppressive to Disease Incited by Rhizoctonia solani Anastomosis Group (AG)-5 and AG-8

ABSTRACT The induction of disease-suppressive soils in response to specific cropping sequences has been demonstrated for numerous plant-pathogen systems. The role of host genotype in elicitation of the essential transformations in soil microbial community structure that lead to disease suppression has not been fully recognized. Apple orchard soils were planted with three successive 28-day cycles of specific wheat cultivars in the greenhouse prior to infestation with Rhizoctonia solani anastomosis group (AG)-5 or AG-8. Suppressiveness to Rhizoctonia root rot of apple caused by the introduced isolate of R. solani AG-5 was induced in a wheat cultivar-specific manner. Pasteurization of soils after wheat cultivation and prior to pathogen introduction eliminated the disease suppressive potential of the soil. Wheat cultivars that induced disease suppression enhanced populations of specific fluorescent pseudomonad genotypes with antagonistic activity toward R. solani AG-5 and AG-8, but cultivars that did not elicit a disease suppressive soil did not modify the antagonistic capacity of this bacterial community. When soils were infested prior to the initial wheat planting, all cultivars were uniformly susceptible to R. solani AG-8. However, when pathogen inoculum was added after three growth-cycles, wheat root infection during the fourth growth-cycle varied in a cultivar specific manner. The same wheat cultivar-specific response in terms of transformation of the fluorescent pseudomonad community and subsequent suppression of Rhizoctonia root rot of apple was observed in three different orchard soils. These results demonstrate the importance of host genotype in modification of indigenous saprophytic microbial communities and suggest an important role for host genotype in the success of biological control.