Farmland degradation in the mountains of Nepal: a study of watersheds ‘with’ and ‘without’ external intervention

Amidst growing concerns about farmlands conservation, this paper examines the status of farmlands in two mountain watersheds ‘with’ and ‘without’ external intervention, located in the western hills of Nepal. Information was obtained from a household survey and group discussions conducted during April to September 1999. The severity of soil erosion from farmers' perspectives, density of landslides, soil nutrient balance and change in crop yield have been adopted as indicators of the status of the land. Results of the analysis indicate that land resources in both watersheds are undergoing degradation, though the causes and extent of degradation vary from one type of land to another. Upland crop terraces, locally called bari, are undergoing degradation most seriously under the combined influence of severe soil erosion, landslide and the depletion of soil nutrients. In particular, soil erosion has severely affected nearly half of the upland crop terraces in both watersheds due to a number of natural and anthropogenic factors ranging from weak geological structure to arable agriculture. Landslide and nutrient depletion have affected all types of farmlands except homesteads in both watersheds. Overall, the extent and intensity of land degradation is relatively high in the non‐project area, as farmers were not provided with necessary technical and financial support. A broad strategy has been outlined for effective conservation of farmlands. Copyright © 2002 John Wiley & Sons, Ltd.     

Is conservation tillage suitable for organic farming? A review

Conservation tillage covers a range of tillage practices, mostly non‐inversion, which aim to conserve soil moisture and reduce soil erosion by leaving more than one‐third of the soil surface covered by crop residues. Organic farmers are encouraged to adopt conservation tillage to preserve soil quality and fertility and to prevent soil degradation – mainly erosion and compaction. The potential advantages of conservation tillage in organic farming are reduced erosion, greater macroporosity in the soil surface due to larger number of earthworms, more microbial activity and carbon storage, less run‐off and leaching of nutrients, reduced fuel use and faster tillage. The disadvantages of conservation tillage in organic farming are greater pressure from grass weeds, less suitable than ploughing for poorly drained, unstable soils or high rainfall areas, restricted N availability and restricted crop choice. The success of conservation tillage in organic farming hinges on the choice of crop rotation to ensure weed and disease control and nitrogen availability. Rotation of tillage depth according to crop type, in conjunction with compaction control measures is also required. A high standard of management is required, tailored to local soil and site conditions. Innovative approaches for the application of conservation tillage, such as perennial mulches, mechanical control of cover crops, rotational tillage and controlled traffic, require further practical assessment.     

热带农业生态系统土壤肥力与植物养分综合管理研究进展

The greatest challenge for tropical agriculture is land degradation and reduction in soil fertility for sustainable crop and livestock production.Associated problems include soil erosion,nutrient mining,competition for biomass for multiple uses,limited application of inorganic fertilizers,and limited capacity of farmers to recognize the decline in soil quality and its consequences on productivity.Integrated soil fertility management(ISFM) is an approach to improve crop yields,while preserving sustainable and long-term soil fertility through the combined judicious use of fertilizers,recycled organic resources,responsive crop varieties,and improved agronomic practices,which minimize nutrient losses and improve the nutrient-use efficiency of crops.Soil fertility and nutrient management studies in Ethiopia under on-station and on-farm conditions showed that the combined application of inorganic and organic fertilizers significantly increased crop yields compared to either alone in tropical agro-ecosystems.Yield benefits were more apparent when fertilizer application was accompanied by crop rotation,green manuring,or crop residue management.The combination of manure and NP fertilizer could increase wheat and faba bean grain yields by 50%–100%,whereas crop rotation with grain legumes could increase cereal grain yields by up to 200%.Although organic residues are key inputs for soil fertility management,about 85% of these residues is used for livestock feed and energy;thus,there is a need for increasing crop biomass.The main incentive for farmers to adopt ISFM practices is economic benefits.The success of ISFM also depends on research and development institutions to provide technical support,technology adoption,information dissemination,and creation of market incentives for farmers in tropical agro-ecosystems.     

How the Soil Moves Upward in the Olive Orchards of NW Syria: Sustainability Analysis of a Local Innovation

This paper analyses a local innovation in response to intense soil degradation in olive orchards of north‐west Syria. Farmers developed a practice consisting of quarrying red clayey soil in valley bottoms and applying this soil to hillslope olive orchards with heavily degraded calcareous soils. A biophysical, economic and social analysis of the practice of soil application identified the opportunities and risks of this innovative soil management technique. On the basis of a pairwise comparison of nine adjacent treated and nontreated orchard plots, soil applications were found to increase soil depth by 36%, soil water availability by 28% and total available soil nutrients: potassium (+45%), nitrogen (+12%) and phosphorus (+6%). Olive yield increased by about 40%. A cost–benefit analysis found this practice to be economically viable within a large geographical area, and farmers scored the practice higher than alternative methods. A socio‐economic analysis revealed its widespread adoption among different farmer types. The positive results of soil applications at the farm level explain its fast adoption. However, potential risks – including the further depletion of soil resources and the transfer of soil‐borne diseases – limit the long‐term sustainability of this locally developed practice. Copyright © 2013 John Wiley & Sons, Ltd.     

Soil carbon sequestration in China through agricultural intensification,and restoration of degraded and desertified ecosystems

The industrial emission of carbon (C) in China in 2000 was about 1 Pg yr⁻¹, which may surpass that of the United States (1ċ84 Pg C) by 2020. China's large land area, similar in size to that of the United States, comprises 124 Mha of cropland, 400 Mha of grazing land and 134 Mha of forestland. Terrestrial C pool of China comprises about 35–60 Pg in the forest and 120–186 Pg in soils. Soil degradation is a major issue affecting 145 Mha by different degradative processes, of which 126 Mha are prone to accelerated soil erosion. Total annual loss by erosion is estimated at 5ċ5 Pg of soil and 15ċ9 Tg of soil organic carbon (SOC). Erosion‐induced emission of C into the atmosphere may be 32–64 Tg yr⁻¹. The SOC pool progressively declined from the 1930s to 1980s in soils of northern China and slightly increased in those of southern China because of change in land use. Management practices that lead to depletion of the SOC stock are cultivation of upland soils, negative nutrient balance in cropland, residue removal, and soil degradation by accelerated soil erosion and salinization and the like. Agricultural practices that enhance the SOC stock include conversion of upland to rice paddies, integrated nutrient management based on liberal use of biosolids and compost, crop rotations that return large quantities of biomass, and conservation‐effective systems. Adoption of recommended management practices can increase SOC concentration in puddled soil, red soil, loess soils, and salt‐affected soils. In addition, soil restoration has a potential to sequester SOC. Total potential of soil C sequestration in China is 105–198 Tg C yr⁻¹ of SOC and 7–138 Tg C yr⁻¹ for soil inorganic carbon (SIC). The accumulative potential of soil C sequestration of 11 Pg at an average rate of 224 Tg yr⁻¹ may be realized by 2050. Soil C sequestration potential can offset about 20 per cent of the annual industrial emissions in China. Copyright © 2002 John Wiley & Sons, Ltd.     

Fallow cultivation system and farmers' resource management in Niger,West Africa

A survey was carried out in 136 farm‐households from seven villages in 1995 and 1996 to analyse the traditional fallow cultivation system in Niger. Farmers were asked to give information about land use on their fields, focusing on cropping and fallow periods as well as on cultivation changes compared to the past. In addition, they were interviewed about their management strategies to maintain or improve soil fertility. Millet‐based systems clearly dominate at all sites, either in pure form or intercropped with cowpea, groundnut, sorghum or roselle. At present, almost half of all farmers cultivate their fields on average up to 5 years until it is left fallow. About one‐third use their fields permanently. Most farmers use short fallow periods of 1 to 5 years. Moreover, there was a decrease in the cropping area left fallow, and the fallow period also decreased steadily in the past years. In the mid‐1970s the average fallow period was about 8 years, decreasing to 2.5 years in 1996. The actual fallow periods are too short to allow sufficient positive effects on soil fertility and farmers are aware of this problem. Consequently, farmers employ different fertilization techniques which aim at maintaining or restoring the soil nutrient pool of the fields while providing physical protection against wind and water erosion. Most farmers use animal manure to improve soil fertility and apply mulch from different sources, millet stalks and branches, for soil regeneration. Few farmers employ other strategies such as mineral fertilizer or planting pits. The farmers try to optimize the use of internal and external resources resulting in a mixture of different fertilization and soil protection methods. Internal resources play by far the most important role. Due to the generally limited resource availability farmers concentrate their management efforts on certain areas within each field or on selected fields only. This means a decreased crop production for the individual household and a higher risk of soil degradation because of soil mining or increased erosion risk on the field area where soil fertility management cannot be practised. Copyright © 2002 John Wiley & Sons, Ltd.     

Ongoing and Emerging Questions in Water Erosion Studies

Soil erosion is a threat to food security, especially in regions where the area of arable land is shrinking dramatically because of soil degradation. Research on soil erosion expanded progressively throughout the 20th centu\ry, although a number of unresolved problems persist despite this issue being crucial for the environment and the welfare of society. Some basic unresolved issues, including the absence of a universally accepted definition of soil erosion and disagreement about how to measure it have contributed to a degree of scientific stagnation. Accurate prediction of the response of soils to disturbance is hampered by the dependence of the erosion process on the spatial scale involved, the time lag between the disturbance and the erosion response and the short periods for which data are typically available. We argue that devoting increased attention to the following environmental, demographic, political and societal issues will reinvigorate progress in the field. (i) The relationships between on‐site and off‐site consequences of soil erosion need to be elucidated if the economic and environmental costs are to be adequately assessed. (ii) Effective measures for soil conservation need to focus on spatial patterns of plant cover that reduce sediment connectivity, and most importantly on the relationships between hillslopes and sediment transfer in eroded channels. (iii) The scientific community must be able to identify early warning signs of critical transitions, if irreversible soil degradation is to be prevented. (iv) Consensus needs to be reached concerning the contribution of soil erosion to the carbon cycle. (v) The consequences of climate change on erosion and sediment transport should be investigated in depth. (vi) The general society needs to perceive soil erosion as a critical matter requiring an urgent response. Copyright © 2016 John Wiley & Sons, Ltd.     

Effect of fertilization and irrigation upon NPK composition of corn leaves,on corn yields,and available k in soil

Abstract

Corn (Zea mays L.) was grown for three consecutive years on Congaree loam to measure the effects of rates of N, P, and K fertilization and irrigation on the nutrient concentration of leaves, the level of available K in the soil, and on the yield of corn. Plant nutrients consisting of 0, 56, 140, 224, and 280 kg N/ha; 0, 15, 37.5, 60, and 75 kg P/ha, and 0, 28, 70, 112, and 140 kg K/ha were applied in a central composite rotatable design in each of the three years. All plant residue was removed each year when the corn was harvested, and the plots remained fallow during the winter months. One half of the experiment was irrigated when there was a 50% depletion of available soil moisture in the 0‐ to 46‐cm soil depth.

Leaf composition was affected by fertilization and irrigation. A rapid decrease in available soil K in the 0‐ to 15‐cm depth was evident the first year with all rates of added K. The decline in available soil K was unaffected by irrigation and levels of applied N and P.

There were consistent yield responses each year to added N, no response to added P, and a response to added K only during the second year.     

Landscape-scale soil quality change under different farming systems of a tropical farm in Hainan, China

Abstract. The impact of different tropical farming systems on soil quality was examined using a systematic sampling strategy. Total organic C, pH, extractable P, exchangeable K, bulk density, water stable aggregates, microbial biomass C, cation exchange capacity, soil depth, and clay content were determined. An assessment framework, including a minimum data set, linear scoring functions and weighted additive indices, was used to evaluate the soil quality of a tropical farm growing various crops in Hainan, China. Soil quality was evaluated according to four functions: water availability, nutrient availability, rooting suitability, and erosion resistance. Our results showed that soils were intrinsically lacking in nutrients and vulnerable to degradation, and that these problems were exacerbated by inappropriate management. There was strong evidence that long-term rubber farming caused soil acidification, soil compaction, and depletion of organic matter and nutrients. By contrast, conservation practices in coffee plantations protected or improved organic matter concentration and soil structure, resulting in higher soil quality indices.     

PROJECTED CHANGES IN SOIL ORGANIC CARBON STOCKS UPON ADOPTION OF RECOMMENDED SOIL AND WATER CONSERVATION PRACTICES IN THE UPPER TANA RIVER CATCHMENT,KENYA

Large areas in the Upper Tana river catchment, Kenya, have been over‐exploited, resulting in soil erosion, nutrient depletion and loss of soil organic matter (SOM). This study focuses on sections of the catchment earmarked as being most promising for implementing Green Water Credits, an incentive mechanism to help farmers invest in land and soil management activities that affect all fresh water resources at source. Such management practices can also help restore SOM levels towards their natural level. Opportunities to increase soil organic carbon (SOC) stocks, for two broadly defined land use types (croplands and plantation crops, with moderate input levels), are calculated using a simple empirical model, using three scenarios for the proportion of suitable land that may be treated with these practices (low = 40 per cent, medium = 60 per cent, high = 80 per cent). For the medium scenario, corresponding to implementation on ~348 000 ha in the basin, the eco‐technologically possible SOC gains are estimated at 4·8 to 9·3 × 10⁶ tonnes (Mg) CO₂ over the next 20 years. Assuming a conservative price of US$10 per tonne CO₂‐equivalent on the carbon offset market, this would correspond to ~US$48–93 million over a 20‐year period of sustained green water management. This would imply a projected (potential) payment of some US$7–13 ha⁻¹ to farmers annually; this sum would be in addition to incentives that are being put in place for implementing green water management practices and also in addition to the benefits that farmers would realize from the impact on production of these practices themselves. Copyright © 2012 John Wiley & Sons, Ltd.     

Runoff,soil loss,and nutrient depletion under traditional and alternative cropping systems in the Transmexican Volcanic Belt,Central Mexico

In the Transmexican Volcanic Belt a traditional fallow system is practiced, called “ año y vez ” (AV), which does not benefit soil conservation due to its low level of nutrient recycling and because soil protection is poor during the cultivation year. The objective of the present work was to measure runoff and soil and nutrient losses during three annual cycles (2002–2004) in Central Mexico under AV rotation and two alternative systems: improved traditional (IT) and traditional organic (TO). Soil losses in the three systems were moderate (<1.2 Mg ha⁻¹ y⁻¹) except during 2002, in which significant soil losses were recorded in IT and TO due to the scarcity of plant cover (<20 per cent) that was present throughout the rainy season. During the resting period of the AV system (2003), the annual runoff increased from 19 to about 600 per cent, compared to IT and TO without grazing. The difference in runoff was attributed to an 18 per cent increase in bulk density of soil surface (0–5 cm) caused by cattle trampling while grazing. Nutrient losses in the three treatments were mainly of N, Ca²⁺, Mg²⁺, Na⁺, and K⁺. These results suggest that AV has a higher topsoil degradation effect during the resting year than during the cultivation period. The study shows that incorporating the maize/beans‐black oat rotation and residue cover causes a low runoff response that is important in reducing soil degradation. A spatial analysis is presented of erosion at watershed level for two soil management systems assessed. Copyright © 2009 John Wiley & Sons, Ltd.     

Soil extension needs to be a continuum of learning; soil workshop reflections 10 years on

Effective extension of soil research builds landholder capacity to manage soils productively and sustainably. Government‐funded extension programmes also aim to improve the state of the environment through efficient use of resources and mitigating or preventing further land degradation. To these ends, a soil extension programme aimed at farmers in south‐eastern Australia was conducted during 2005–2008. The programme was designed to equip landholders with the knowledge, skills and confidence to diagnose and address soil constraints, as well as compile spatial information on soil properties. The programme involved four workshops that covered agricultural productivity, soil management and potential off‐site impacts. Workshops were held on‐farm and involved discussion, theory supported with practical exercises, and field visits. More than 1,400 participants were provided with subsidized soil tests to encourage soil monitoring and underpin the workshop theory on land capability and soil constraints (e.g., soil acidity, sodicity, salinity, nutrient decline and toxicities). Prior to the course, most participants did not regularly soil test so training on monitoring protocols was provided. The soil data indicated considerable phosphorus deficiencies, low organic carbon levels, and acidity across both cropping and pasture systems. Participant knowledge and land management intentions were tracked throughout the workshop series using surveys. The surveys identified a positive shift in the knowledge, understanding and confidence of most participants. However, a follow‐up survey 10 years later indicated that these changes may not have been broadly sustained. Based on our study, we recommend continued engagement of landholders along a learning pathway to maximize investment in soil extension.     

Farmer perception of soil erosion and investment in soil conservation measures: emerging evidence from northern Taraba State,Nigeria

To combat soil erosion in the northern part of Taraba State, Nigeria, farmers are of major importance. Their perceptions vitally influence the levels of support and investment associated with solving problems of soil erosion through adoption of practices that are alternative to those in current use, including approaches focused on soil conservation. The objective of this study was to evaluate how farmer perceptions of soil erosion influence their investments in soil conservation, particularly soil or stone bunds, their applications of organic amendments and inorganic fertilizers and other soil conservation practices. In the study area, we undertook a field plot experiment and carried out a survey, using open‐ and closed‐ended questions. Water erosion and depletion of fertility were taken as the main indicators of soil erosion. The results of the experiment showed that farmers were aware of and perceived both indicators as having increased over the past decade. Farmer investments in water erosion control (3.7 US$/ha) and the prevention of soil fertility depletion (37.8 US$/ha) in the study area were found to be limited. The results also showed that awareness of water erosion was only marginally correlated with investment in water erosion control (χ² = 4.906, P = 0.09) and not associated with investments in soil fertility control measures (χ² = 0.175, P = 0.92). Those farmers who identified depletion of soil fertility as a problem, based on erosion, were not significantly more likely to make greater investments in soil conservation (χ² = 0.947, P = 0.62) but did invest more in fertility measures (χ² = 3.199, P = 0.20). Hence, further research is needed to determine other factors that may influence farmer investment in soil conservation, especially factors related to socio‐economic characteristics of farm households, institutional and technological innovations and field characteristics that were not addressed in this study.     

Effects of wastewater irrigation on soil and cabbage‐plant (brassica olerecea var. capitate cv. yalova‐1) chemical properties

The use of wastewater for irrigation is increasingly being considered as a technical solution to minimize soil degradation and to restore nutrient contents of soils. The aim of this study is to increase fertility and minimize degradation of soils irrigated with wastewater exposed to different purification treatments. A field experiment was conducted to investigate the effects of control and irrigation with wastewater, which had undergone different purification treatments, on macro‐ and micronutrient distribution within the soil profile and nutrient contents of cabbage (Brassica olerecea var. Capitate cv. Yalova‐1) in Erzurum, Turkey. Wastewater irrigation and preliminary treatment–wastewater irrigation significantly affected soil chemical properties especially at 0–30 cm soil depth and plant nutrient contents after one year. Application of wastewater increased soil salinity, organic matter, exchangeable Na, K, Ca, Mg, plant‐available P, and micro‐elements and decreased soil pH. Wastewater increased also yield and N, P, K, Fe, Mn, Zn, Cu, B, and Mo contents of cabbage plants. Undesirable side effects were not observed in plant heavy‐metal contents, due to salinity and toxic concentrations of metals from the application of wastewater to soil.     

The relationship between farmer opinion of suitable conditions for nutrient application,soil moisture deficit and weather

Slurry spreading is a beneficial nutrient recycling activity on livestock farms, but nutrients may be lost to the environment. On‐farm decision support based on the Hybrid Soil Moisture Deficit Model and weather data has the potential to forecast when conditions are best for slurry application. Such an approach will only be accepted by farmer–stakeholders if it is consistent with scientific evidence. The objective of this article was to establish whether farmers have a broadly similar opinion of soil and weather conditions suitable for slurry spreading as those derived from the water balance approach. A mobile phone short message service (SMS) survey permitted rapid and efficient collection of information from farmers in relation to trafficability, weather forecast, nutrient efficiency and storage limitations. Farmers’ response followed seasonal trends, with spring and summer the being the best seasons for nutrient utilization while their view of inappropriate conditions for spreading was consistent with restrictions imposed by current legislation in Ireland. However, the winter ban on nutrient spreading had the adverse effect of encouraging farmers to spread slurry just before and immediately after the closed period when application is prohibited. In general, farmers have similar reasons for their management decisions but they may need further assistance with the forecast of soil moisture and weather conditions at critical times.     

Better land husbandry in Honduras: towards the new paradigm in conserving soil,water and productivity

Land shortages are forcing more smallholder farmers to cultivate tropical steeplands. Resulting accelerated soil erosion is being countered by the promotion of soil conservation (SC) technologies, such as cross‐slope barriers, which aim to reduce soil loss and preserve land productivity. However, farmer adoption rates tend to be low. This is often attributed to the farmers' conservatism or lack of education. Research in Honduras's steeplands demonstrates that farmers value SC, provided that it promotes agricultural production. Field research from 1995–98, involving farmed test plots on slopes greater than 35 per cent (19 degrees), demonstrates that at least one typical SC technology—live barriers of Vetiveria zizanioides (vetiver grass)—has little or no impact on maize yield. This means that farmers see little benefit from their investment in the SC method. They find that erratic rainfall, pests and diseases and a lack of economic resources are far greater threats to their livelihoods than soil erosion. Consequently, SC has a low priority. Keeping soil in place avoids major off‐farm disbenefits. However, the SC technique tested here made no discernible difference to slope foot sediment yields during the life of this study. In sum, a new approach is needed. Promoting ‘Better Land Husbandry’ strategies, which seek to combine farmers' concerns about productivity with conservationists' concerns about reducing soil erosion—often via cover‐management—seem to be the best way forward. Copyright © 2002 John Wiley & Sons, Ltd.     

Assessing the effect of crop residue removal on soil organic carbon storage and microbial activity in a no‐till cropping system

Changes in agricultural management strategies have received much attention in recent years with a view to increasing or maintaining the amount of carbon (C) sequestered as soil organic C (SOC). In many parts of the world, minimum or no‐till management has been promoted as a means of improving soil quality, reducing losses of erosion and potentially increasing SOC stocks. However, no‐till systems can become problematic and potentially disease‐prone, especially due to high crop residue loadings. Consequently, residue removal either by harvesting or burning off may be employed to reduce these pressures. Here, we examined the effect of crop residue removal on C storage in soil that had been under no‐till management for 20 yr. We predicted improved physical properties (i.e. lower bulk density) and greater microbial activity under the residue retention soils due to greater readily available C and nutrients derived from crop residues. In contrast, we predicted relative reductions in SOC in the no residue soils due to a lack of available residue‐derived C for microbial use. Residue removal caused a relative C loss from the soil, which was related to C input, amount of nutrient availability and microbial activity. We demonstrate the importance of maintaining crop residue cover in no‐till cropping systems for soil function and highlight the potentially deleterious effects of changing management strategy to increased residue harvesting or removal by burning.     

Erosion modelling approach to simulate the effect of land management options on soil loss by considering catenary soil development and farmers perception

The prevention of soil erosion is one of the most essential requirements for sustainable agriculture in developing countries. In recent years it is widely recognized that more site‐specific approaches are needed to assess variations in erosion susceptibility in order to select the most suitable land management methods for individual hillslope sections. This study quantifies the influence of different land management methods on soil erosion by modelling soil loss for individual soil‐landscape units on a hillslope in Southern Uganda. The research combines a soil erosion modelling approach using the physically based Water Erosion Prediction Project (WEPP)‐model with catenary soil development along hillslopes. Additionally, farmers' perceptions of soil erosion and sedimentation are considered in a hillslope mapping approach. The detailed soil survey confirmed a well‐developed catenary soil sequence along the hillslope and the participatory hillslope mapping exercise proved that farmers can distinguish natural soil property changes using their local knowledge. WEPP‐model simulations show that differences in soil properties, related to the topography along the hillslope, have a significant impact on total soil loss. Shoulder and backslope positions with steeper slope gradients were most sensitive to changes in land management. Furthermore, soil conservation techniques such as residue management and contouring could reduce soil erosion by up to 70 percent on erosion‐sensitive slope sections compared to that under tillage practices presently used at the study site. The calibrated model may be used as a tool to provide quantitative information to farmers regarding more site‐specific land management options. Copyright © 2008 John Wiley & Sons, Ltd.     

Soil degradation in Kabd area,southwestern Kuwait City

Adverse environmental impacts of human activities are the main causes of soil degradation in the desert of Kuwait in general, and in Kabd area in particular. In this study, assessment of soil degradation in open and protected sites has been carried out using field measurements and laboratory investigations. The overall status of vegetation is nearly twice as low in vegetation cover in the open sites than in the protected ones due to overgrazing and off‐road transport. Compaction of soil due to pressure exerted on the soil by vehicles led to a significant reduction in its porosity, permeability and infiltration capacity. The average infiltration rate of the compacted soils is 51 per cent lower than that of the non‐compacted soils. The bulk density of the non‐compacted soils is 3.4 per cent lower than that of compacted soil. The average topsoil resistance of compacted soils has increased by 83 per cent in comparison with non‐compacted soil. Using the least squares method a relation between infiltration rate (IR) and penetration resistance (PR) of the topsoil for the study areas is found (i.e. IR = −0.148 PR + 1.85 with R² = 25 per cent). Soil strength within the soil profile shows maximum penetration resistance readings at 11.5 cm depth in average in compacted soils, while it shows maximum readings at 34.6 cm depth in average in non‐compacted soils. The adverse changes in the chemical properties due to soil compaction is also investigated. A restoration plan is needed in order to reduce land degradation. Copyright © 2002 John Wiley & Sons, Ltd.