Rotation/Succession Systems Affects Springtails (Hexapoda: Collembola) Abundance in Cash Crops Under No Tillage Cultivation

Acknowledging the bio indicator importance of springtails (Hexapoda: Collembola) for soil quality, this study aimed to determine the abundance of these arthropods in different systems of rotation/succession with commercial and cover crops, while also verifying the agricultural factor associated to these arthropods’ population. In the Instituto de Desenvolvimento Rural do Paraná (IAPAR-EMATER), during six years, areas with differing crops in rotation/succession adopting the no-tillage system were studied. For each system, chemical analyses of the soil were conducted and the number of captured springtails in pitfall traps was counted. The phytosanitary products applied during the evaluations and the quantity of vegetal cover remaining after harvest were considered as well. No difference was found between the rotation/succession systems in relation to chemical soil attributes, however the largest number of springtails was found in crop covers from corn, Brachiaria sp., and canola. These crop covers, including wheat, resulted in the highest straw dry mass. When removing the system in which the predecessor crop had the highest quantities of fungicide application, a positive correlation (r = 0.63; p < 0.01) was found, between springtail abundance and highest amount of straw after the harvest. If no fungicide applications occur, the crops with the largest amount of vegetal cover favor springtail populations.

Pedogenical Distribution of some Micronutrients in Prevailing Sub Great Soil Group in Iraq

The study included the analysis of (341) samples from eight pedons cover most of the prevailing sub great soil groups in Iraq, which are (Typic Torrifluvents, Typic Torrients, Typic Gypsiorthids, Typic Calciorthids, Aquollic Salorthids, Typic Chromoxerects, Typic Xerrochrepts and Typic Calcixerects) to study the pedogenetic distribution of total and bioavailable content of the manganese, zinc, copper, and iron also its relationship with some soil properties. Results showed significant differences between the studied regions of total content of microelements, the bioavailability content also showed a significant deference between the studied regions. The physical and chemical soil properties clearly affected on their content of micronutrient and 77% of the studied samples were below the critical limit for zinc, but 65% of the studied samples were under the critical limit for iron. This refers to the response of the cultivated crops in such sub great soil groups to the addition of Zn and Fe fertilizers, also pedogenetic distribution of the content of these microelements showed a decrease with depth and compatible with the distribution of each of the separated clay and organic matter and decrease with the increase in the soil content of calcium carbonate.

The Effect of Soil Sampling Density and Spatial Autocorrelation on Interpolation Accuracy of Chemical Soil Properties in Arable Cropland

Knowledge of the relationship between soil sampling density and spatial autocorrelation with interpolation accuracy allows more time- and cost-efficient spatial analysis. Previous studies produced contradictory observations regarding this relationship, and this study aims to determine and explore under which conditions the interpolation accuracy of chemical soil properties is affected. The study area covered 823.4 ha of agricultural land with 160 soil samples containing phosphorus pentoxide (P2O5) and potassium oxide (K2O) values. The original set was split into eight subsets using a geographically stratified random split method, interpolated using the ordinary kriging (OK) and inverse distance weighted (IDW) methods. OK and IDW achieved similar interpolation accuracy regardless of the soil chemical property and sampling density, contrary to the majority of previous studies which observed the superiority of kriging as a deterministic interpolation method. The primary dependence of interpolation accuracy to soil sampling density was observed, having R2 in the range of 56.5–83.4% for the interpolation accuracy assessment. While this study enables farmers to perform efficient soil sampling according to the desired level of detail, it could also prove useful to professions dependent on field sampling, such as biology, geology, and mining.

Chemical characters of disease suppressive and conducive soil of Moler on shallot in Brebes Central Java

In the latest years, a disease epidemy of Moler caused by Fusarium oxysporum f.sp. cepae have just occurred in Brebes Central Java. The disease intensity, however, varies between the shallot production lands. Some lands show suppressive with disease intensity lower than 5%, and others are conducive to disease intensity over 50%. It is interesting that in Brebes occur suppressive and conducive soil to moler disease. The suppressiveness may be determined by environmental conditions, including chemical soil characters. This paper reports the chemical character of suppressive and conducive soil to moler disease in Brebes. The evidence shows that the suppressive soil is more fertile than that conducive one. The suppressive soil is chemically characterized by significantly higher organic mineral, C-organic, P-available, K-exchangeable, and Cation Exchange Capacity than that conducive one.

The effect of organic fertilizers on the physico-chemical and agrochemical properties of sod-podzolic soils

Studies of the effect of litter chicken manure applied in doses of 500-1000 t/ha showed a significant increase in the humus content in soils up to 2.8-5.2%, led to an increase in the content of thermophilic microflora in soils up to 12 · 105 CFU/ g, to an increase in the content of mobile phosphates up to 1200 mg/kg. However, the content of mobile forms of heavy metals (Pb, Zn, Cu, Ni) also increased. The increase in humus content in soils positively correlated with the content of mobile phosphates (r up to 0.5). Keywords: SOD-PODZOLIC SOIL, FERTILIZERS, CHICKEN MANURE, AGROCHEMICAL AND PHYSICO-CHEMICAL SOIL PROPERTIES

Physical and Chemical Soil Properties of Mangrove Forests in Vietnam

Recently the area of mangrove (evergreen) forests growing along the coast of Vietnam has been significantly increased by artificial afforestation under the recognition of their ecological role and economic importance. Protection mangrove forests are the largest among all mangrove forests in Vietnam. They act as a belt to prevent coastal roads from erosion and damage due to tides, storms, and tsunamis. However, their role in coastal soil formation is still poorly studied. Soil formation in mangrove forests is influenced by many factors including the following: woody vegetation, tidal saltwater, precipitation, and mountain runoff. The ability of soil to retain water, nutrients, ions, and some other physical and chemical properties is closely related to the soil texture. Long-term monitoring of the soil texture and the content of nutrients in the soil of mangrove forests in the Dam Bay area of the Nha Trang Bay allowed us to distinguish 2 groups of soil phases: typical laterite soil in natural mangrove forests and in rhizophore plantings of 2004 and poorly developed laterite soil in cultural cenoses of 2007 and 2013 and in the littoral zone. These two groups have differences in the soil texture depending on the time of stand formation. The total amount of gravel, aleurite, and silt in the first group of soils is higher than that in the second group. The concentrations of nutrients (phosphorus and nitrogen content) in the soil of mangrove forests is quite high, though it gradually decreases from the soil of natural mangrove forests to the littoral zone. In order to effectively prevent erosion of soils and improve their physical and chemical properties, artificial mangrove forests should continuously be grown along the coast lines of the Nha Trang Bay in the Khanh Hoa province, Vietnam. For citation: Phan T.H., Kovyazin V.F., Zvonareva S.S., Nguyen T.H.T., Nguyen T.L. Physical and Chemical Soil Properties of Mangrove Forests in Vietnam. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 5, pp. 9–21. DOI: 10.37482/0536-1036-2021-5-9-21

STABILIZATION OF SUBGRADE SOIL USING CALCIUM LIGNOSULFONATE AND GRANITE DUST- A REVIEW

India is a geographically diverse country with varied soil types in different places. As a result, stabilising techniques are employed to enhance those regions with low bearing capacity. Soil strength is improved using both mechanical and chemical stabilising techniques. In the mechanical approach, mechanical energy is employed (rollers, plate compactors, tempers, etc., depending on the choice or type of the soil) to enhance soil characteristics by compaction. Chemical Soil Stabilization is a chemical approach that involves blending and combining chemical additions to improve the soil’s engineering qualities. Chemical substances such as calcium lignosulfonate, granite dust, cement, and fly ash were added in. Although calcium lignosulfonate may stabilise a wide variety of soil types, it works best in soft soils and clay soils with moderate to medium flexibility. Granite dust is primarily used in clay soils with a lot of flexibility. KEY WORDS: Calcium lignosulfonate, Granite dust, soil, stabilization, subgrade

Effects of Habitat Loss on the Ecology of Pachyphytum caesium (Crassulaceae), a Specialized Cliff-Dwelling Endemic Species in Central Mexico

Cliff-dwelling plant species are highly specialized and adapted to a vulnerable, fragmented, and are mostly endemic, narrowly-distributed and threatened. As a contribution to the conservation efforts of endemic cliff-dwelling species, this study provides an overview of the effects of habitat loss on the abundance and distribution of Pachyphytum caesium (Crassulaceae) due to human disturbances. To achieve this objective, we first conducted a retrospective analysis from 2003–2013 to assess the effects of land use change on the abundance of P. caesium. Secondly, we estimate the abundance and distribution of P. caesium throughout the study area, as well as analyze the effect of rock-climbing activities on the density and population structure of P. caesium. The results suggest differences in population abundance among sites is due to the adverse effects of habitat loss. P. caesium presents a very restricted distribution with small and fragmented populations. In addition, guava agriculture has a significant impact on the chemical soil properties of the hillsides, causing a significant effect on the occurrence of P. caesium, while sport activities remove both the soil and the plants from the cliffs. According to the results, P. caesium is classified as a plant species with extremely small populations (PSESP), and it is highly vulnerable to habitat disturbance. Its conservation is thus a priority to ensure its permanence.

Non-Chemical Soil Fumigation for Sustainable Strawberry Production in Southern Italy

In intensive strawberry production, monoculture is a common practice worldwide; however, prolonged replanting can cause plant disorders and jeopardize profitable cultivation of this highly valuable crop. To mitigate replanting problems, the strawberry industry is still highly dependent on chemical fumigation. Given the increasing regulatory restrictions and concerns about human and environmental risks from fumigants use, there is a growing interest in the adoption of effective, non-chemical alternatives. Two non-chemical soil fumigation practices, i.e., anaerobic soil disinfestation (ASD) and bio-fumigation with biocide plants (BIOFUM), were tested against chemical fumigation by chloropicrin + 1,3-dichloropropene mixture (STANDARD) and untreated (UNTREAT) control in a 2-year trial established in a commercial strawberry farm in Southern Italy (40°25’ N, 16°42′ E). Overall, the alternative practices provided consistently better results than UNTREAT; whereas, compared to STANDARD, their performance was significantly different in the two years: in 2018/19 season the alternative practices registered a 20% (ASD) and 39% (BIOFUM) marketable yield loss compared to STANDARD, while in the 2019/20 season yield differences were not significant. Although both practices appear promising as eco-friendly alternatives to chemical fumigation, in this short-term trial ASD performed better than BIOFUM both in terms of yield and fruit size, resulting in a more advanced stage for practical adoption.