Fallow Grassland Research Articles

Runoff and erosion reduction benefits of vegetation during natural succession on fallow grassland slopes

Vegetation restoration is an effective and important measure for controlling soil erosion in arid and -arid regions. Both its aboveground and underground parts play a crucial role in controlling surface runoff and soil detachment on slopes. But how much the parts of vegetation contribute to the runoff and sediment reducing benefits of rill erosion on slopes is unclear. We used grassland slopes at four successional stages for simulated scouring experiments to observe how successional vegetation community structures, root characteristics, and soil structures contribute to erosion and sand production. Initial flow production time increased, and total runoff decreased. Under the scour intensities, the 11-year slope had the lowest flood peak and volume and the greatest runoff reduction benefit. The 25-year slope had the lowest sand peak and volume and the greatest sediment reduction benefit. As scour intensity increased, runoff reduction effect of vegetation at the successional stages decreased; the sediment reduction benefit remained high. PLS-PM analysis showed that the indirect effects of the aboveground and underground parts of vegetation on sand production were −0.364 and −0.439, respectively. Aboveground parts mainly embodied the regulation of runoff, in which stem count, humus mass, and biomass were the main factors affecting runoff and sand production. Underground parts mainly reflected their soil structure improvement, in which root volume density, root surface area density, and root mass density are the main explanatory variables. The direct effects of runoff and soil structure on slope rill erosion were 0.330 and −0.616, respectively, suggesting the stability of soil structure is the primary factor affecting the sand production, not erosion energy. The results provide a reference for scientific assessment of the key role of natural vegetation restoration in regional soil erosion control and the development of biological measures for soil and water conservation on the slopes of the Loess Plateau.

Long-term grassland diversity-productivity relationship regulated by management regimes in northern China

Grasslands are the most extensively distributed terrestrial ecosystems on Earth, providing a range of ecosystem services that are vital for sustaining human life and critical for sustainable development at the global scale. However, the relationship between the two most important attributes of grassland, plant diversity, and productivity, remains controversial even after many years of research. Here, we develop an analysis of covariance (ANCOVA) model based on decadal-scale experimental data from a degraded meadow steppe in northeastern Inner Mongolia, China to quantify the response of aboveground biomass (AGB) to plant species diversity under varying management regimes. We report that AGB responds negatively to the plant diversity in fallow grasslands and positively in grazing grasslands, transiting from negative to positive in mowing grasslands as mowing became more frequent. We show that the changing diversity-productivity relationships are driven by changes in species composition of the plant community, given the significant productivity gap between rare and non-rare species. This highlights the role of management in regulating the diversity-productivity relationships in grasslands. These results not only provide provocative insights into the relationships between plant diversity and productivity but also support more sustainable use and management of grassland resources.

Az évjárat hatásának pontosítása feltétlen juhlegelők koratavaszi növényállomány fejlettségére

The feasibility of first grazing of extensive sheep pastures was investigated by monitoring the height of grassland in the spring of 2022 and 2023 at the Karcag Research Institute, focusing on the effect of vintage in this manuscript. For 6 grassland plots with different parameters, potentially suitable for early spring sheep grazing, in a meadow on solonyec soil with no level of inputs due to environmental subsidies, we refined soil temperature, soil moisture and height of grassland vegetation at the same time of year. For both years, it was concluded that it is justified to start grazing sheep on the fallow grassland and the pasture forest.

Monitoring the Degradation of Semi-Natural Grassland Associations under Different Land-Use Patterns

The topicality of our research topic is justified by the significant change in traditional grassland management in the grassland areas of the Pannonian Basin. Due to several factors, the proportion of fallow grassland, and in parallel of over-exploited pastures, is continuously increasing. In the medium term (11 years), the effects of fallowing (Z), annual mowing (M), mowing and grazing (meadow treatment M + G), and permanent overgrazing (OG) as treatments on the population structure of grassland plants were investigated in a semi-natural grassland community in the Solonyec soil. It was found that the lowest degradation rates in the studied grassland biotope were obtained for the treatment presenting the utilisation pattern of mowing the main grassland phytomass followed by sheep grazing of the coltgrass. The highest degradation levels, which threatened the condition of the grassland community, were measured for the treatment presenting overgrazing with sheep at the end of the experimental period.

Investigation of Carbon-Dioxide-Emissions from Underutilized Grassland between 2019 and 2020

Climate change-induced extreme changes are making phytomass yields of extensive grasslands in continental areas increasingly dependent on the season. This situation is exacerbated, inter alia, by the decline in grazing livestock production due to a lack of quality labour, and thus by an increase in the proportion of unused or under-utilised grassland. In our experiments, we have refined the effects of a decade of unused/abandonment, mulch, mowing and meadow utilisation on carbon emissions, soil moisture and soil temperature during two different types of years. We found that unused/abandonment grassland with accumulated duff in the absence of utilization had the highest carbon dioxide emission values in different years, even at lower soil moisture values. Our results confirm the fact that fallow grasslands can be considered a source of risk due to their increased greenhouse gas emissions.

Passive regeneration of subtropical grassland vegetation in a chronosequence of ex‐cultivated fields in Australia

AbstractAimIn Australia, natural grasslands largely occur on fertile clay soils and have consequently been extensively cultivated since European settlement. Other studies have demonstrated that passive restoration of subtropical grassland is possible in environments where there is substantial native remnant vegetation in the surrounding landscape. This study examined a chronosequence of abandoned fields to investigate the recovery of fragmented grassland in a matrix of cultivated land with significant exotic species that may impede succession.LocationDarling Downs, Queensland, Australia.MethodsIn this study we surveyed a chronosequence of ex‐cultivated subtropical grasslands in Queensland's Darling Downs, where only 1% of the original grasslands remain. Floristic surveys were carried out in 80 fallow sites up to 51 years old, and data were compared with 16 previously surveyed remnant grasslands on the same land type.ResultsRichness of native species increased with time since cultivation and approached, but did not reach, that of remnant grasslands after 51 years, whereas the richness of exotics declined with time since cultivation. Rainfall and grazing positively and negatively affected exotic plant abundance respectively and these factors had no significant direct or indirect effect on the native species richness. In terms of composition, fallow grasslands supported 54% of the native plant species from remnant grasslands after 51 years. The native perennial grasses Dichanthium sericeum and Aristida leptopoda were the only dominant species in the remnants that were present in more than 60% of the fallow grasslands. Of the species from remnants that were “missing” from fallow sites, most were native perennial forbs and grasses. Compositional dissimilarity of fallow grassland to remnant grasslands remained high after 51 years (78%). Grassland species that are uncommon in nearby hill woodlands were preferentially absent in fallow grassland and this partly explains the slow compositional recovery.ConclusionIn a highly fragmented landscape, passive restoration is only partially effective. The restoration of grassland is probably enhanced by repositories of native seeds from hill woodlands that are too rocky to cultivate. However, some species may have to be actively reintroduced to achieve complete recovery. In this landscape, where grazing is a dominant land use, exotic species do not seem to impede succession.

Heterogeneity in Event-Based Soil Hydrologic Response to Different Land Use Types in Upper River Njoro Catchment, Kenya

Soil hydrologic response depends on the soil characteristics such as infiltration capacity, porosity, organic matter content and bulk density. Knowledge on the dynamics of these soil parameters and soil hydrologic response as a result of different land use types is crucial for formulation and adoption of proper soil and water conservation techniques for increased agricultural production. In this research, soil hydrologic response to different land use types is evaluated. Four land use types were purposely selected. These included natural forest, deforested land, fallow agricultural land and grassland. Soil samples were collected and soil hydraulic and hydrological properties that included soil texture, bulk density, saturated hydraulic conductivity, porosity and organic matter content were determined in the soil laboratory. The evaluated soil hydrological response parameters included runoff coefficients, infiltration rate, water repellency and ponding time. The findings showed that the highest and lowest mean bulk density of 1.36 and 0.96 g/cm3 was recorded for deforested and natural forest land respectively. The highest mean saturated hydraulic conductivity (170.21cm/day), porosity (0.62) and organic matter content (4.63%) were observed in the natural forest while the lowest values (24.78cm/day, 0.47 and 0.75%) respectively were found in the deforested land. High water repellency (100.34 cm/hr) and runoff coefficient (0.0077) was recorded in the deforested areas. The findings of this indicate how different land use types affect on-site hydrologic response and generation of stream flow in the catchment hence providing baseline data for future soil and water relations research.

Soil–air greenhouse gas fluxes influenced by farming practices in reservoir drawdown area: A case at the Three Gorges Reservoir in China

The Three Gorges Reservoir (TGR) in China has large water level variations, creating about 393 km2 of drawdown area seasonally. Farming practices in drawdown area during the low water level period is common in the TGR. Field experiments on soil-air greenhouse gas (GHG) emissions in fallow grassland, peanut field and corn field in reservoir drawdown area at Lijiaba Bay of the Pengxi River, a tributary of the Yangtze River in the TGR were carried out from March through September 2011. Experimental fields in drawdown area had the same land use history. They were adjacent to each other horizontally at a narrow range of elevation i.e. 167–169 m, which assured that they had the same duration of reservoir inundation. Unflooded grassland with the same land-use history was selected as control for study. Results showed that mean value of soil CO2 emissions in drawdown area was 10.38 ± 0.97 mmol m−2 h−1. The corresponding CH4 fluxes and N2O fluxes were −8.61 ± 2.15 μmol m−2 h−1 and 3.42 ± 0.80 μmol m−2 h−1. Significant differences and monthly variations among land uses in treatments of drawdown area and unflooded grassland were evident. These were impacted by the change in soil physiochemical properties which were alerted by reservoir operation and farming. Particularly, N-fertilization in corn field stimulated N2O emissions from March to May. In terms of global warming potentials (GWP), corn field in drawdown area had the maximum GWP mainly due to N-fertilization. Gross GWP in peanut field in drawdown area was about 7% lower than that in fallow grassland. Compared to unflooded grassland, reservoir operation created positive net effect on GHG emissions and GWPs in drawdown area. However, selection of crop species, e.g. peanut, and best practices in farming, e.g. prohibiting N-fertilization, could potentially mitigate GWPs in drawdown area. In the net GHG emissions evaluation in the TGR, farming practices in the drawdown area shall be taken into consideration.

Spring-Thaw Nitrous Oxide Emissions from Reed Canarygrass on Wetness-Prone Marginal Soil in New York State

In temperate climates, a significant fraction of annual emissions of nitrous oxide (N2O) from agricultural land can occur during soil thaw in late winter and early spring. The objective of this study is to determine the impact of land use change from long-term fallow grassland to managed perennial grass crops on these thaw-related N2O emissions, and to identify field-scale drivers that influence emissions. Using static chambers, we monitored mid-afternoon N2O fluxes during the 2013 spring thaw from March 27 to April 7, observing fallow grassland and second year reed canarygrass (Phalaris arundinaceae L., v. Bellevue) over a short topographical gradient. Soil temperature, soil moisture and residual above-ground biomass were also observed, as were hourly air temperature and precipitation. Fluxes of N2O were generally low (-9.8 to 21.3 μg N2O-N m-2 hr-1) except for one observation of 77.6 μg N2O-N m-2 hr-1. Hot-moment analysis, non-parametric statistical tests, and ANOVA results showed that downslope positions converted to managed and fertilized grass had significantly higher N2O emissions compared to the fallow and upslope positions. We found that these downslope managed grass sites had mean soil moisture of 75.0 % water filled pore space (WFPS) and less insulating residual above-ground biomass than the fallow grassland. Our results suggest that converting fallow grassland to managed perennial grass cropping systems for bioenergy or other uses could increase springthaw N2O emissions in wetness-prone areas.

The Structure of Plant Communities of Fallow Land in the System of Protective Forest Plantations in Dry Steppes

The article presents data on the species composition and coenotic structure of the plant commu-nities of 20-year-old fallow grasslands in the system of protective forest plantations. It was found that the speed of successional dynamics depends on the distance from protective forest plantations.

Deforestation and cultivation mobilize mercury from topsoil

Terrestrial biomass and soils are a primary global reservoir of mercury (Hg) derived from natural and anthropogenic sources; however, relatively little is known about the fate and stability of Hg in the surface soil reservoir and its susceptibility to change as a result of deforestation and cultivation. In southwest Ohio, we measured Hg concentrations in soils of deciduous old- and new-growth forests, as well as fallow grassland and agricultural soils that had once been forested to examine how, over decadal to century time scales, man-made deforestation and cultivation influence Hg mobility from temperate surface soils. Mercury concentrations in surficial soils were significantly greater in the old-growth than new-growth forest, and both forest soils had greater Hg concentrations than cultivated and fallow fields. Differences in Hg:lead ratios between old-growth forest and agricultural topsoils suggest that about half of the Hg lost from deforested and cultivated Ohio soils may have been volatilized and the other half eroded. The estimated mobilization potential of Hg as a result of deforestation was 4.1mgm−2, which was proportional to mobilization potentials measured at multiple locations in the Amazon relative to concentrations in forested surface soils. Based on this relationship and an estimate of the global average of Hg concentrations in forested soils, we approximate that about 550Mmol of Hg has been mobilized globally from soil as a result of deforestation during the past two centuries. This estimate is comparable to, if not greater than, the amount of anthropogenic Hg hypothesized by others to have been sequestered by the soil reservoir since Industrialization. Our results suggest that deforestation and soil cultivation are significant anthropogenic processes that exacerbate Hg mobilization from soil and its cycling in the environment.

Knowing the way home: strong philopatry of a highly mobile insect species, Brenthis ino

Mobility is crucial for the maintenance of viable metapopulations, but quantitative data to evaluate risks due to insufficient individual mobility of focal insect species are mostly lacking. We selected the butterfly Brenthis ino, a species typically confined to wet fallow grasslands in Central Europe and performed a mark–release–recapture study in a 3.2 ha study area with one big and one small patch of suitable habitat from 22 June to 23 July 2010. The position of each butterfly capture was measured with a GPS and transferred into a GIS. In total, we marked 984 individuals in 1,545 capture events and estimated that the cumulative population size was 2,400 individuals. The initial increase of adult males proceeded much faster than for females, similar to the protandrous population build-up known from other butterflies. Moved distances for both sexes usually did not exceed 80 m, and about 40 % of all individuals used less than 2 % of the available suitable habitat. All individuals switching to the other patch returned later to their patch of origin, confirming that B. ino is highly philopatric. We conclude that low effective mobility in B. ino produces much smaller home ranges than suggested by merely observing flight activities in the field, and that low tendencies towards long-distance movements significantly hamper the maintenance of metapopulations when patch density decreases due to landscape fragmentation.

Carbon and nitrogen contents and greenhouse gas fluxes of the Eurasian steppe soils with different land-use histories located in the Arkaim museum reserve of South Ural, Russia

The effects of different land-use histories on contents of soil carbon (C) and nitrogen (N) and fluxes of greenhouse gases [carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O)] measured using the closed chamber method were investigated in the Arkaim museum reserve located in the South Ural of Russia. A natural forest site (NF) and two grassland sites that had different land-use histories (CL: cropland until 1991; PST: pasture until 1991; both sites have been fallow for 18 years) were selected for soil sampling and gas flux measurements. The vegetation in NF was mainly Betula pendula Roth. with steppe cherry and grassy cover. Perennial grasses (Stipa spp., Festuca spp. and others) have been planted in CL and PST since 1991 to establish reserve mode, and the projective cover of these plants were > 90% in both sites in 2009. Soil samples were taken from the A horizon in the three sites, and additionally samples of the O horizon were taken from NF. The contents of soil C and N [total C, total N, soluble organic C, soluble N and microbial biomass C (MBC)] in the O horizon of NF were the largest among all investigated soils (p < 0.05). Additionally, the total C, total N and MBC in PST were significantly larger than in CL (p < 0.05). Positive CO2 fluxes (i.e., CO2 efflux) in all three investigated sites were observed. The CO2 efflux in NF was significantly larger than in CL and PST (129, 30 and 25 mg C m−2 hour−1, respectively, p < 0.05), although there was no significant difference in values of CO2 efflux between CL and PST. There were no significant differences in the fluxes of CH4 and N2O among NF, CL and PST (p > 0.05). Our current research indicated that, in soils of the Eurasian steppe zone of Russia, total C, total N and MBC were affected not only by current land-use (i.e., fallow grassland vs. natural forest) but also by past (until 18 years ago) land-use.

Changes in Bacterial Community Structure of Agricultural Land Due to Long-Term Organic and Chemical Amendments

Community level physiological profiling and pyrosequencing-based analysis of the V1-V2 16S rRNA gene region were used to characterize and compare microbial community structure, diversity, and bacterial phylogeny from soils of chemically cultivated land (CCL), organically cultivated land (OCL), and fallow grass land (FGL) for 16 years and were under three different land use types. The entire dataset comprised of 16,608 good-quality sequences (CCL, 6,379; OCL, 4,835; FGL, 5,394); among them 12,606 sequences could be classified in 15 known phylum. The most abundant phylum were Proteobacteria (29.8%), Acidobacteria (22.6%), Actinobacteria (11.1%), and Bacteroidetes (4.7%), while 24.3% of the sequences were from bacterial domain but could not be further classified to any known phylum. Proteobacteria, Bacteroidetes, and Gemmatimonadetes were found to be significantly abundant in OCL soil. On the contrary, Actinobacteria and Acidobacteria were significantly abundant in CCL and FGL, respectively. Our findings supported the view that organic compost amendment (OCL) activates diverse group of microorganisms as compared with conventionally used synthetic chemical fertilizers. Functional diversity and evenness based on carbon source utilization pattern was significantly higher in OCL as compared to CCL and FGL, suggesting an improvement in soil quality. This abundance of microbes possibly leads to the enhanced level of soil organic carbon, soil organic nitrogen, and microbial biomass in OCL and FGL soils as collated with CCL. This work increases our current understanding on the effect of long-term organic and chemical amendment applications on abundance, diversity, and composition of bacterial community inhabiting the soil for the prospects of agricultural yield and quantity of soil.

Botanical analysis of fallow grasslands existing in mountain conditions

The investigations were carried out in the years 2000- -2004 on permanent grassland in Czarny Potok (Beskidy Mts. - 650 a. s. l.). Botanical census was conducted by using Klapp's method on 26 plots (18 random selected plots and 8 controls). The whole floristic material was subjected to numerical classification. As a result, three main types of plots with the dominating species of: &lt;i&gt;Juncus effusus&lt;/i&gt; (1), &lt;i&gt;Cirsium arvense&lt;/i&gt; (2) and &lt;i&gt;Deschampsia caespitosa&lt;/i&gt; (3), were distinguished. &lt;i&gt;Poa trivialis&lt;/i&gt; was the dominating species of the control plots. Results of the floristic and habitat analysis confirmed that the main factors determining the formation of meadow and pasture communities are as follows: the method of use, water relations and soil nutrient availability. It was found that idle glades are characterised by degraded sward of the average (the sward patches with the domination of &lt;i&gt;Deschampsia caespitosa&lt;/i&gt;) or low use value (the swards patches with the domination of &lt;i&gt;Cirsium arvense&lt;/i&gt; and &lt;i&gt;Juncus effusus&lt;/i&gt;). The deterioration of the feeding value of the fallow plots is an effect of their high weed infestation, which in turn results, in this case, from habitat changes as a consequence of the cessation of use and earlier errors made in cultivation measures. Both high and low soil moisture, with improper meadow management, accelerated the weed infestation of the sward, what in turn lowers its use value. Cutting and fertilisation positively affect the use value of plant habitats, what was confirmed by the botanical and habitat analysis of the control plots with the domination of &lt;i&gt;Poa trivialis&lt;/i&gt;, which is known to be of good use value.

Identification of General Patterns of Nutrient and Labile Carbon Control on Soil Carbon Dynamics Across a Successional Gradient

Carbon (C) inputs and nutrient availability are known to affect soil organic carbon (SOC) stocks. However, general rules regarding the operation of these factors across a range of soil nutrient availabilities and substrate qualities are unidentified. “Priming” (stimulated decomposition by labile C inputs) and ‘preferential substrate utilization’ (retarded decomposition due to shifts in community composition towards microbes that do not mineralize SOC) are two hypotheses to explain effects of labile C additions on SOC dynamics. For effects of nutrient additions (nitrogen and phosphorus) on SOC dynamics, the stoichiometric (faster decomposition of materials of low carbon-to-nutrient ratios) and ‘microbial mining’ (that is, reduced breakdown of recalcitrant C forms for nutrients under fertile conditions) hypotheses have been proposed. Using the natural gradient of soil nutrient availability and substrate quality of a chronosequence, combined with labile C and nutrient amendments, we explored the support for these contrasting hypotheses. Additions of labile C, nitrogen (N), phosphorus (P), and combinations of C and N and C and P were applied to three sites: 2-year fallow grassland, mature grassland and forest, and the effects of site and nutrient additions on litter decomposition and soil C dynamics were assessed. The response to C addition supported the preferential substrate hypothesis for easily degradable litter C and the priming hypothesis for SOC, but only in nitrogen-enriched soils of the forest site. Responses to N addition supported the microbial mining hypothesis irrespective of C substrate (litter or SOC), but only in the forest site. Further, P addition effects on SOC support the stoichiometric hypothesis; P availability appeared key to soil C release (priming) in the forest site if labile C and N is available. These results clearly link previously contrasting hypotheses of the factors controlling SOC with the natural gradient in litter quality and nutrient availability that exists in ecosystems at different successional stages. A holistic theory that incorporates this variability of responses, due to different mechanisms, depending on nutrient availability and substrate quality is essential for devising management strategies to safeguard soil C stocks.

Changes in soil physico-chemical properties and microbial functional diversity due to 14 years of conversion of grassland to organic agriculture in semi-arid agroecosystem

Soil physico-chemical properties, microbial biomass, and functional microbial diversity were investigated in two adjacent fields located in a semi-arid dryland farming region of Maharashtra state, India. In organically cultivated field (OCF) large annual inputs of composted cow manure, no tillage and no removal of crop residues is being practiced for the past 14 years. The neighboring plot which was not cultivated for the same period remained as fallow grassland (FGL) served as check for comparison. Soil samples collected from OCF had higher pH, moisture, total organic carbon and nitrogen, microbial biomass, C and N, and enzymatic activities compared to FGL soil. Microbial community structure in the two soils was assessed, using Biolog Eco and GN2 plates. OCF soil showed significant ( P = 0.01) increase of microbial diversity and evenness, suggesting an improvement of functional microbial diversity. Principal component analysis (PCA) separates the two soil samples based on 10 most discriminating carbon sources for each with the maximum positive and negative scores. To the best of our knowledge this is the first study on soil quality and microbial functional diversity of soil in a semi-arid region indicating that conversion from FGL to OCF led to significant soil quality improvement due to the enhanced microbial functional diversity.

Morphological characterization of solute flow in a brown earth grassland soil with cranefly larvae burrows (leatherjackets)

Cranefly larvae, often known as leatherjackets, are a well known horticultural pest, damaging garden lawns, plants and sporting venues. They burrow into the soil and feed on the roots of plants. However, little is known about the hydrological role of leatherjackets. Such information is needed by modellers to improve water and solute models. This paper investigates flow through leatherjacket burrows in grassland fields. It compares infiltration rates, patterns of dye tracer and pore size distributions in a grassland system with and without leatherjackets. It also compares these distributions to those in an adjacent cropped tillage system which was largely devoid of leatherjackets. Dye tracer distributions show the leatherjacket burrows to act as active preferential flowpaths for water during percolation. A significant relationship between leatherjacket density and infiltration rate was found which took the form of an exponential curve. Leatherjackets were predominately found in the upper 30 cm of the grassland where there was a significantly greater volume of pores that were greater than 2 mm than in the arable soil and where visible macropores, including those open to the surface were significantly more common, covered a significantly larger cross-sectional area and were more circular in cross-sectional area. Leatherjacket burrows significantly reduced the spread of water into the surrounding soil and thereby acted as effective conduits for water to bypass the soil matrix in the upper 30 cm of the grassland. Mean dye coverage was greater at between 30 and 36 cm in the grassland soil profile, where leatherjacket burrows ended, than any other parts of the soil profile deeper than 8 cm. Such dye distributions were rare in the arable soils where very few leatherjackets were present. In some regions fallow grassland is increasing in area in response to environmental policy. Therefore, since infiltration significantly increased with leatherjacket density, consideration of their role in macropore flow will be necessary to understand the full range of hydrological and water quality implications of conversion from arable to fallow grassland management.

MODIFICATIONS OF THE SOIL STRUCTURE UNDER THE EROSION AND CROPS INFLUENCE IN THE CONDITION FROM NORTHWESTERN ROMANIA

SUMMARY The paper presents the results carried out in Orade a on the hill with slope of 8% in the plot for determination of the soil and water flow. The variants studied were: clean fallow grassland, wheat, maize seeded on the direction of the level curves and maize seeded from top to valley. Soil structure was determined at the top and at the base of the flow plot, on 0-10 cm depth and 10-20 cm depth; the determination method used was the Cseratzki one. The size of the macroaggregates were: Φ >5 mm; Φ=3.1-5 mm; Φ=1.1-3.0 mm; Φ=0.25-1 mm. The biggest differences between the structure degre e from the top of the hill in comparison with the base was registered in the vari ant with clean fallow: 48.6% (37.44% vs 55.65%) on 0-10 cm depth and 31.9% (39.15% vs 51.67%) on 10-20 cm. this variant was followed by the variant with maize seeded from top to valley: 39.3% (40.98% vs 57.08%) on 0-10 cm depth and 27.1% (43.28% vs 55%) on 10-20 cm. In the variant with maize seeded on the direction of the level curve the differences we re smaller than in maize seeded from top to valley: 12.3% (47.94% vs 53.84%) on 0-10 cm and 11.2% (45.58% vs 50.94%) on 10-20 cm. In wheat the differences were smaller: 8% (50.22% vs 54.26%) on 0-10 cm and 8.5% (50.06% vs 54.30%) on 10-20 cm. The biggest values of the structure degree was registered in the variant with grassland; this variant registered the smallest differences between structure degree on 0-20 cm in the top (55.56%) in comparison with the base (56.82%) of the flow plot. The researches emphasized the importance for establ ishing the crops (grassland, wheat) with good protection against soil erosion and to se ed the maize on the direction of the level curves and not from top to valley. As a result, the differences between the degree structure from top of the hill and base will not increase.

Effects of different land-use types on soil quality in the hilly area of Rawalakot Azad Jammu and Kashmir

Vegetative cover plays an important role for the quality of soil especially in hilly and mountainous areas such as Azad Jammu and Kashmir where erosion is a major threat to the ecosystem and productivity. The study focuses on the impact of land-use types on soil quality by measuring the differences in chemical and physical properties at three sites in adjacently located natural forest land (forest), fallow grassland (grass) and arable land (arable). Soil samples from 0-15 and 15-30 cm depth were collected and examined for particle distribution, dry bulk density, organic matter (OM), pH, macro- and micro-nutrients. Land-use types had a significant effect on primary soil particle distribution. Highest clay content was found in forest and highest sand content in arable. Forest had relatively the highest levels of OM, macro- and micro-nutrients and arable the lowest. Most of the properties of the 0-15 cm surface level of grass were similar to those observed in the 15-30 cm level in forest. Arable exhibited lowest nutrient status and poorest physical conditions, indicating a degrading effect of arable cultivation practices on soil. Grass and arable showed, compared to forest, a 30–60% average increase in bulk density and 26–66% average decrease in OM. Regression analysis showed a significant correlation of OM with available phosphorus and potassium while it had negative correlation with dry bulk density and pH. Natural vegetation appeared to be a main contributor of soil quality as it maintained the organic carbon stock, and increased the nutrient status of soil and is therefore important for sustainable development of Azad Jammu and Kashmir and other similar areas. Furthermore, OM was shown to be an important indicator of soil quality.