328 research outputs found
Genesis and Clay Mineralogy of Soils on Different Geomorphic Surfaces in Mahan-Joupar area, Central Iran
No full textInvestigation of Soil Health and Sustainable Management in Rice-Based Production Systems
No full textEvaluation of soil quality indicators in paddy soils under different crop rotation systems
No full textSoil quality, by definition, reflects the capacity to sustain plant and animal productivity, maintain or enhance
water and air quality, and promote plant and animal health. Soil quality assessment is an essential issue in
soil management for agriculture and natural resource protection. This study was conducted to detect the effects of
four crop rotation systems (rice-rice-rice, soya-rice-rice, fallow-rice and pea-soya-rice) on soil quality indicators
(soil moisture, porosity, bulk density, water-filled pore space, pH, extractable P, CEC, OC, OM, microbial
respiration, active carbon) in paddy soils of Verona area, Northern Italy. Four adjacent plots which managed
almost similarly, over five years were selected. Surface soil samples were collected from each four rotation
systems in four times, during growing season. Each soil sample was a composite of sub-samples taken from 3
points within 350 m2 of agricultural land. A total of 48 samples were air-dried and passed through 2mm sieve,
for some chemical, biological, and physical measurements. Statistical analysis was done using SPSS. Statistical
results revealed that frequency distribution of most data was normal. The lowest CV% was related to pH. Analysis
of variance (ANOVA) and comparison test showed that there are significant differences in soil quality indicators
among crop rotation systems and sampling times. Results of multivariable regression analysis revealed that soil
respiration had positively correlation coefficient with soil organic matter, soil moisture and cation exchange
capacity. Overall results indicated that the rice rotation with legumes such as bean and soybean improved soil
quality over a long time in comparison to rice-fallow rotation, and this is reflected in rice yield
Assessment of soil biological quality index (QBS-ar) in different crop rotation systems in paddy soils.
No full textNew methods, based on soil microarthropods for soil quality evaluation have been proposed by some Authors.
Soil microarthropods demonstrated to respond sensitively to land management practices and to be correlated with
beneficial soil functions. QBS Index (QBS-ar) is calculated on the basis of microarthropod groups present in a
soil sample. Each biological form found in the sample receives a score from 1 to 20 (eco-morphological index,
EMI), according to its adaptation to soil environment. The objective of this study was to evaluate the effect of
various rotation systems and sampling periods on soil biological quality index, in paddy soils. For the purpose
of this study surface soil samples (0-15 cm depth) were collected from different rotation systems (rice-rice-rice,
soya-rice-rice, fallow-rice and pea-soya-rice) with three replications, and four sampling times in April (after field
preparation), June (after seedling), August (after tillering stage) and October (after rice harvesting). The study
area is located in paddy soils of Verona area, Northern Italy. Soil microarthropods from a total of 48 samples
were extracted and classified according to the Biological Quality of Soil Index (QBS-ar) method. In addition soil
moisture, Cumulative Soil Respiration and pH were measured in each site. More diversity of microarthropod
groups was found in June and August sampling times. T-test results between different rotations did not show
significant differences while the mean difference between rotation and different sampling times is statistically
different. The highest QBS-ar value was found in the fallow-rice rotation in the forth soil sampling time. Similar
value was found in soya-rice-rice rotation. Result of linear regression analysis indicated that there is significant
correlation between QBS-ar values and Cumulative Soil Respiration
Soil and Archeology. The Costanciacus project in the frame of the Venice lagoon evolution
No full text
Enzyme dynamics in paddy soils of the rice district (NE Italy) under different cropping patterns
No full textRecently, the widespread interest on soil enzymes is due to the need to develop sensitive indicators of soil quality that reflect the effects of land management on soil and assist land managers in promoting long-term sustainability of terrestrial ecosystems. The activities of six important enzymes involved in C, N, P, and S cycling were investigated in a paddy soil from the Veneto region, Italy, in four different rotation systems (rice-rice-rice, soya-rice-rice, fallow-rice and pea-soya-rice) with three replications in April (after field preparation, field moist condition), June (after seedling, waterlogged soil condition), August (after tillering stage of rice, waterlogged soil condition) and October (after rice harvesting, drained soil condition) over the 2012 growing season. Our results demonstrated that soil enzyme activities varied with rotation systems and growth stages in paddy field. Compared with field moist soil, drained soil condition resulted in a significant increase (P < 0.05) of β-glucosidase, arylsulfatase, alkaline and acid phosphatases, leucine aminopeptidase (except of F-R), and chitinase activities in all rotations, while compared with drained soil, waterlogging (in month of June, the early period of waterlogging) significantly decreased (P<0.05) β-glucosidase, alkaline and acid phosphatases, leucine aminopeptidase (except of P-S-R), arylsulfatase, chitinases. Soil organic-C was positively correlated with acid and alkaline phosphatases, and arylsulfatase while ß-glucosidase, chitinases and leucine aminopeptidase were not significantly correlated to soil organic-C. Enzyme activities were always correlated among them
Potentially toxic elements in foodcrops (Triticum aestivum L., Zea mays L.) grown on contaminated soils
No full textPlants can uptake potentially toxic elements from the soil and accumulate themin the roots or translocate them
to the aerial parts. Excessive content of these elements in edible parts can produce toxic effects and, through the
food chain and food consumption, result in a potential hazard for human health. In this study soils and plants
(Triticum aestivum L. and Zea mays L.) from a tannery district in North-East Italy were analyzed to determine
the content of potentially harmful elements (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, P, Pb, S, Zn and V). According
to the national legislation, the area is contaminated by Cr, Ni, Cu, Zn, Cd and V. The distribution of contaminants
along the soil profile shows a general tendency to metal accumulation at surface as expected for anthropogenically
enriched sites. Major anthropogenic origin was detected for Cr, Ni (from industrial activities), Zn, Cu, Cd
(fromagriculture practices). Major nutrients (K, P and S) and some micronutrients (Cu, Zn, Mgand Mn) are easily
absorbed and translocated, while other potentially toxic elements (Ca, Fe, Al, Cd, Cr, Ni, Pb and V) are not accumulated
in the seeds of the two considered species. However, the two edible species proved differently able to
absorb and translocate elements, and this suggests to consider separately every species as potential PHEs transporter
to the food chain and to humans. Chromiumconcentrations in seeds and other aerial parts of the examined
plants are higher than the values found for the same species and for other cereals grown on unpolluted soils.
Comparing the Cr levels in edible parts with recommended dietary intake, besides other possible Cr sources
(dust ingestion, water), there seems to be no health risk for animal breeding and population due to the consumption
of wheat and maize grown in the area
Assessment of background levels of total macro- and microelements in plants and paddy soils in the Venetian territory (NE Italy)
No full textDetermination of macro- and microelements in rice has attracted great attention over the centuries, since rice is one of the most consumed food in the world. High concentrations of toxic elements in paddy soils would enhance the uptake of these elements by rice resulting in human health hazard.
Macro- and micronutrient concentrations in soils and plants from the rice district in the Venetian territory (NE Italy) have been determined by ICP-MS spectrometry, with the following aims:
- to determine background levels of elements;
- to assess deficiency/toxicity levels in soils and plants;
- to calculate the Translocation Factor (TF) from soil to plants.
Four rice plots with different rotation systems were sampled from seedling time to harvesting; sampling of soils and plants was carried out 4 times during growing season.
The soils present high levels of Fe and Mg, while other elements (B, Cu, Mn, Ni, Zn) are below the Italian guidelines. P, S and Mg deficiency in plants were observed in all rotations, while Fe concentration was above the phytotoxicity threshold. Slight contamination was also observed for Ni. Translocation of Cu, Ni, Zn, P from soil to root was found to be >1 while Mg, Ca and Mn had the lowest translocation factor. Micronutrients (B, Cu, Fe, Ni) are easily translocated to leaves and grains (TF ≤1). Therefore, rice is assumed as an accumulator plant of Cu, Mn, Ni and Zn, whereas it is as an indicator plant for Fe. It could be useful in contaminated-sites restoration by phytostabilization. Hazard for resident population is limite
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