Effect Of Different Farming Systems Research Articles

Dynamic stability of mineral-associated organic matter: enhanced stability and turnover through organic fertilization in a temperate agricultural topsoil

Soil organic matter (SOM) plays a vital role for soil quality, sustainable food production and climate change mitigation. It is common knowledge that SOM consists of different pools with varying qualities, quantities, and turnover times. However, it is still poorly understood how mineral and organic fertilization affects the formation and stabilization of mineral-associated organic matter (MAOM) and how long it can remain there. Here, we report on the long-term effects of different farming systems on the stability and turnover of the fine silt and clay-sized MAOM fraction (<6.3 μm) of a Haplic Luvisol (0–20 cm) in the DOK long-term trial (Switzerland). We compared three farming systems with contrasting fertilization (CONMIN = pure mineral, CONFYM = mineral + organic, BIODYN = pure organic) with an unfertilized control (NOFERT) between 1982 and 2017. We performed specific surface area (SSA) measurements on fractionated MAOM samples (<6.3 μm) from 1982 to 2017, before and after removal of OM, measured the 14C activity of all samples during the entire period and estimated the mean residence time (MRT) with a model taking into account ‘bomb 14C’ and radioactive decay. We found constant MAOM-C contents under organic fertilization. Results of SSA analysis indicate best conditions for MAOM-C stabilization under organic fertilization and different sorption mechanisms in MAOM between farming systems with and without organic fertilization. The modelled MRTs were significantly higher in NOFERT (238 ± 40 yrs) and CONMIN (195 ± 27 yrs), compared to CONFYM (138 ± 18 yrs) and BIODYN (140 ± 19 yrs), implying a high C turnover (i.e. more active MAOM) at high C contents under organic fertilization. Our findings show that MAOM is not the dead OM but corroborates the concept of ‘dynamic stability’. Continuous OM inputs from organic fertilizers and their rapid and constant turnover are needed to stabilize the “stable” MAOM-C fraction.

Effects of different farming systems and crop protection strategies on the health status and yield of carrots Daucus carota L. ssp. sativus

The aim of this study was to evaluate the effects of farming systems on the health status of carrots cv. Koral and root yield components. The organic farming system promoted the spread of damping-off of seedlings in the first two wet growing seasons and Alternaria leaf blight in the last growing season with normal precipitation levels. At harvest, the severity of root diseases was low. During storage, carrot roots were susceptible to soft rot, Sclerotinia rot and dry rot. In the integrated farming system, the symptoms of mixed rot were more observed at harvest and after storage, and of dry rot after storage. In the organic farming system, the symptoms of dry rot were more noted at harvest, and the symptoms of crater rot were more observed after storage. During storage, the applied crop protection methods significantly suppressed mixed rot in the integrated farming system, and dry rot in the organic system. The isolation of potential pathogens from carrot petioles and roots confirmed their participation in the disease process. Negative correlations were found between the severity of Alternaria leaf blight vs. the marketable yield of carrots and single root weight in both production systems in selected years of the study.

Effect of Different farming systems on management of insect pests and population of Natural Enemies in Groundnut and Blackgram

Effect of Different farming systems on management of insect pests and population of Natural Enemies in Groundnut and Blackgram

Farming systems in sheep rearing: Impact on growth and reproductive performance, nutrient digestibility, disease incidence and heat stress indices.

The experiment was conducted with an intent to know the effect of different farming systems on the growth performance, nutrient digestibility coefficients, reproductive traits, disease incidence, heat stress indices, and cost economics of Nellore sheep. The study includes two parallel trials to prevent the influence of age on heat stress indices (panting score and erythrocyte osmotic fragility (EOF)). One hundred and twenty lambs (60 ram-lambs and 60 ewe-lambs) were allotted in a randomized block design under extensive, semi-intensive, and intensive systems for trial I, whereas trial II include eighteen rams assigned to the three respective farming systems in a completely randomised design. Both, season (summer) and grazing practice increased the panting score and EOF. The heat stress indices were positively correlated (P<0.01) with dry-bulb temperature and temperature-humidity index (THI) and inversely correlated (P<0.01) to relative humidity. Allotting the sheep to intensive system increased (P<0.001) weight gain and average daily gain with higher effect in males compared to females. The parameters of asymptotic weight (A), integration constant (B), and maturation rate were higher for intensive males. The male Nellore lambs had higher asymptotic weight and lower maturity rate than females, irrespective of the rearing system. Intensive sheep revealed a higher dry matter intake, digestibility coefficients, feed conversion ratio. The instantaneous bite mass (IBM) was higher for Commelina benghalensis, while instantaneous bite frequency (IBF), instantaneous intake rate (IIR) were higher for Cyanodon dactylon and amaranthus viridis, respectively. The proportion of intakes were highest for Stylo hemata followed by Cynodon dactylon and Tridax procumbens species. No differences were observed for the weight at puberty, oestrus cycle length, oestrus duration, conception percent, gestation period, and lambing percent in three rearing systems; however, the age at puberty was lower (P<0.001) and the birth weight was higher (P<0.001) for sheep reared under intensive farming system. Highest disease incidence was observed in rainy and winter seasons, particularly in sheep reared under extensive system. The capital expenditure was same for the three rearing systems, while the recurring expenditure was higher for Intensive farming system. The gross income and net income were higher for intensive system on account of higher weight gains. However, the higher returns per rupee of expenditure project the extensive farming as an ideal rearing system for small farmers and entrepreneurs with a low initial capital.

Isolation and Characterization of Beneficial Microorganisms in Organic, Semi-Organic and Conventional Fertilizer Treated Agricultural Field Soil and Comparison of Bacterial Richness

The effect of different farming systems on microbial communities in agricultural environment was investigated in the present study. Depending on the present farming trend, the microbial distribution in agricultural soils treated with organic, semi-organic and conventional fertilizers was analyzed. A total of 20 soil samples were collected from different types of agricultural fields of Bangladesh Agricultural Research Institute (BARI, Gazipur). Microorganisms playing beneficial roles in soil such as nitrogen fixation (e.g. Rhizobium sp., Azotobacter sp.), phosphate solubilization (e.g. Bacillus sp., Pseudomonas sp., Phosphobacteria) and auxin production (e.g. Pseudomonas sp., Serratia sp. and Bacillus sp.) were evaluated from each of the samples. The results revealed that agricultural fields treated with chemical fertilizers showed lower microbial count than that of organic fertilizer treated agricultural fields’ soil samples. In addition, organic fertilizers amended field soils have higher phytohormone (Auxin) activities, phosphate solubilization bacteria and other bacterial richness compared to chemical fertilizer applied field soil.

Different agricultural practices affect soil carbon, nitrogen and phosphorous in Kilombero -Tanzania

Converting natural and semi-natural vegetation to agriculture is currently the most significant land use change at global scale. This conversion leads to changes in soil nutrients and increased CO2 emissions. However, knowledge of how soil organic carbon and nutrients change under various farming management is still limited, especially for small scale farming systems. This study evaluated the effects of different farming systems on soil organic carbon (SOC), total nitrogen (TN) and total phosphorous (TP) in subsistence farming at Kilombero, Tanzania. We applied an in-situ experimental setup, comparing maize and rice farming with and without irrigation and difference in fertilizers, with replicated soil sampling at five soil depths to a depth of 60 cm. The results show that irrigation had a positive effect on profile-averaged concentrations of SOC and TN, while fertilization had a positive effect on TN. Higher concentrations and stocks of TN were found in maize field soils compered to rice fields. In the vertical profile, irrigation and fertilization had positive effects on concentrations of SOC and TN of top soil layers, and the interaction between irrigation and fertilization extended the effect to deeper soil layers. Our results indicate that moderate irrigation and fertilization can help to improve carbon storage and nutrient availability (TN) in small-scale farming soils in Africa.

Reproductive performance and body condition score of Deccani sheep during various physiological stages in different farming systems

The research was carried out to study the effect of different farming systems on reproductive traits and body condition score in Deccani sheep. Ewes (36), 9–12 months of age, were divided in to 3 groups, viz. intensive (T1), semi-intensive (T2) and extensive farming system (T3) with 12 ewes in each group following completely randomized design. The results revealed that, body weight at puberty in intensive group (17.6 kg) was significantly higher than extensive (16.3) group. Age at puberty in extensive group was significantly higher (338 days) than intensive group (290 days). The conception rate in intensive group was 75%, which was higher than semi-intensive and extensive (58.3 and 66.6% respectively). Intensive group had achieved significantly higher body weight at lambing (24.74 kg) than semi-intensive (23.12 kg) and extensive (22.23 kg). Birth weight of lambs in intensive group (2.5 kg) was significantly higher than semi-intensive (1.98 kg) and extensive groups (1.82 kg). Length of estrus cycle and duration of oestrus differed nonsignificantly in different farming systems. BCS values were significantly higher during pregnancy in intensive group. BCS near parturition (48 h near) and BCS 3 months (post-parturition) was significantly higher in intensive as compared to semi-intensive and extensive. BCS (48 h after parturition) was significantly higher in intensive and semi-intensive systems with respect to extensive system. It can be concluded that reproductive traits and body condition score were higher in intensive system compared to other systems because care of life stages through provision of concentrate feed, with minimal body energy loss can be assured in intensive farming system.

Productive performance, body condition score and carcass characteristics of Deccani lambs reared under different farming systems

The present study was carried out to assess the effect of different farming systems on productive performance, body condition score and carcass characteristics of Deccani lambs. Thirty-six weaned lambs having 3 months of age were divided into three groups with twelve lambs in each group in under intensive (T1), semi-intensive (T2) and extensive (T3) farming systems. The comparative mean dry matter intake (kg/day) and (kg/100kg BW) was significantly (p less than 0.05) higher in T1 group when compared to other groups. T2 group had significantly (p less than 0.05) higher DM intake (kg/day) than T3 group. The mean values of Average daily gains in Deccani lambs were significantly (p less than 0.05) higher in T1 group compared to T2 and T3 groups. The feed efficiency was significantly (p less than 0.05) higher in T1 compared to T2, T3 groups. Statistically significant difference was found in BCS at six months of age (p less than 0.05) between T1 and T3 groups. BCS at 9, 12 months and overall BCS, there was a significant (p less than 0.05) difference between T1 and T3 groups. T1 group had higher pre-slaughter weight, hot carcass weight, meat %, fat% and meat: bone ratio thanT2 and T3. The dressing yields were comparable. The weights of other offals (heart, kidney, spleen, testicles, blood, head and lung and trachea) were comparable. The findings of this study indicated that the intensive and semi-intensive system of rearing could be useful for mutton production. In extensive system, which is predominant in India should change its facet by enriching the grazing land resources as well by the supplementation of required plane of nutrition during growth and special life stages viz., gestation, puberty, post lambing and finisher stages for achieving optimum productivity.

The productivity of two yellow lupine (Lupinus luteus L.) cultivars as an effect of different farming systems

Between 2011 and 2015, a two-factor field experiment on yellow lupine was conducted in Gorzyń, Poland (52°34'07''N, 15°54'33''E). The first-order factor was the farming technology: low-input (LI; without fertilization and chemical protection); medium-input (MI; medium level of fertilization and chemical protection) and high-input (CONV; high level of fertilization and chemical protection). The second-order factor was the cultivar (indeterminate cv. Mister and determinate cv. Perkoz). The research assessed the productive and economic effects of two yellow lupine cultivars grown in different farming systems. The weather conditions significantly influenced the yield in consecutive years of the research. A change from the LI farming system to the MI and CONV systems increased the seed yield by 13.1% and 22.0%, respectively. The research also showed differences in the yield of the cultivars under study. The indeterminate cv. Mister yielded more seeds than the determinate cv. Perkoz (1.95 t/ha vs 1.81 t/ha). The research also showed that when the EU subsidies were added, the value of production increased along with the cultivation intensity. However, an increase in the outlay on industrial means of production in higher-intensity technologies caused a decrease in the gross agricultural income value.

Activity of Dehydrogenases as an Indicator of Soil Environment Quality

Activity of dehydrogenases (DHs) indicates the presence of viable and physiologically active (physiologically active or physiological activity) microorganisms. Their presence (activity) in soil is correlated with the content of organic carbon, microorganisms, nitrifying activity and microbial respiration. Determination of DHs activity allows to control changes in soil microbial population and is considered as an important parameter of soil quality. The aim of the study was to determine the effects of different farming systems on the enzymatic activity in soil under winter wheat. The research was conducted in the years 2014–2016 on long-term field experiment under two different farming systems (ecological and conventional) at the IUNG (PIB) Experimental Station located in Osiny (Lublin Voivodeship), Poland. Each farming system differs in crop rotation system and whole agrotechnics, which have been adapted to its specificity. Determination of DHs activity was performed using Casida et al.’s (1964) method with modifications. Measured DHs activity was expressed in milligrams of triphenyl formazan (TPF) per 100 g of soil within 24 hours. The results showed that ecological farming system beneficially influenced soil environment.

Effect of different farming systems on physiological response, blood parameters and endocrinological profiles in Deccani sheep

The result from revealed that T3 group have significantly (P&lt;0.05) higher respiratory rate, pulse rate and rectal temperature than T1 and T2 groups. Similarly T1 group has significantly (P&lt;0.05) higher Haemoglobin concentration than T2 and T3 groups. Packed cell volume revealed, T3 group has significantly (P&lt;0.05) higher value than T2 and T1 groups. T1 and T2 groups have significantly higher glucose concentration than in T3 group. Similar observation was reported in total protein content. SGOT concentration revealed that significant (P&lt;0.05) difference was observed among the groups and T3 group has significantly higher value than other groups whereas SGPT level was significantly higher in T3 and T2 groups than in T1 groups. Endocrinological profiles such as (T3) triiodothyronine and (T4) thyroxine revealed that T1 group have significantly higher level than T2 and T3 groups and T2 group had significantly (P&lt;0.05) higher T3 and T4 value than in T3 group. Similarly, significantly (P&lt;0.05) higher cortisol was recorded in T3 group over T2 and T1 groups and T2 and T1 groups were comparable. It was found that the intensive system of rearing has higher beneficial effect on comfort and productive performance for sheep farming in the tropical conditions. In the other 2 systems, the stress need to be reduced by supplementation of higher plane of nutrition, electrolyte supplementation during extreme summer and creation of waterbodies in the path of grazing and provision of shade and shelter for the sheep flocks while on long hours of grazing are essential.

Effects of long-term use of different farming systems on some physical, chemical and microbiological parameters of soil quality

AbstractThe aim of this study was to compare the effects of different farming systems (organic, integrated, conventional and monoculture) on some soil properties as: bulk density, contents of readily-dispersible clay, organic matter and particulate organic matter, and enzymatic activity measured in terms of the intensity of fluorescein diacetate hydrolysis. Soil under permanent grass was used as a control. The study was conducted on the 20 years lasting field experiment. Samples of Haplic Luvisol soil were collected twice a year on fields under winter wheat from the layers of 0-5, 5-10, 15-20, and 30-35 cm. Within arable soils the soil under organic farming contained the greatest amount of organic matter, which influenced strongly the readily-dispersible clay content, especially in the layer of 5-20 cm. The readily-dispersible clay content in soil under organic farming was 3 times lower, as compared to the conventional and monoculture farming. The highest contents of particulate organic matter 6.2 and 3.5 mg g−1air dry soil, on average were measured in the 0-5 cm layer of control soil and soil under organic farming, respectively. Also, soil under organic farming and control soil from the depth of 0-5 cm showed 2-2.5 times greater activity of microorganisms in fluorescein diacetate hydrolysis than soil under conventional and monoculture farming. Increase of concentration of organic matter in soil under organic farming decreased soil bulk density. Statistical analysis showed significant correlations between studied parameters of soil quality and confirmed their effectiveness as indicators of disturbances in soil environment.

Digestive enzyme activity in the intestine of Nile tilapia (Oreochromis niloticus L.) under pond and cage farming systems.

The effect of different farming systems (cage, pond) upon digestive enzyme activities of Nile tilapia was evaluated. Juvenile Nile tilapia (87.61±1.52g) were simultaneously cultured in pond and cage systems during 90days. Cages used nutritional biphasic plan (35 and 32% crude protein-CP feeds) and ponds used nutritional triphasic plan (35, 32 and 28% CP feeds). Biometric measurements were monthly performed for adjustments in feeding regimes and removal of intestine tissues to evaluate the performance of enzyme activities. Total proteolytic, amylase and lipase activities were not statistically different between the treatments throughout the periods analyzed (31, 63 and 94days of culture). However, trypsin and chymotrypsin activities were higher with 31 and 63days of culture in fish from pond system, suggesting that natural food may have influenced these activities. A positive correlation was observed between the recommended concentration of essential amino acids for Nile tilapia and specific aminopeptidases activity in fish cage system. Substrate-SDS-PAGE revealed 12 active proteolytic bands in both systems. However, integrated density (ID) values were higher in the bands of ponds. Specimens of either cage or pond exhibited five bands of amylolytic activity. Fish from cage and pond systems showed the highest values of ID within 31days of cultivation. In this study, the complexity of digestive functions could be verified for animals maintained under commercial conditions. Some of the assessed enzymes may show adaptations of their activities and/or expression that allow the fish to achieve a more efficient nutrient assimilation.

Comparative Study on In Vitro Anti-Proliferative and Apoptotic Effects of Organic and Non-Organic Tea Extracts

This study compared the anti-proliferative and apoptotic effects of organic and non-organic Sabah tea on cancer cell lines. Anti-proliferative assays showed that the tea extracts were capable of inhibiting the growth of MCF-7 and HeLa cells. The IC50 values for MCF-7 and HeLa were 20.9 ± 2.6 to 39.3 ± 0.8 and 38.5 ± 3.8 to 42.0 ± 2.3 μg/mL, respectively. Statistical differences were observed in MCF-7 cells treated with organic and non-organic tea extracts. However, no differences were found in HeLa cells. Morphological changes were observed in both treated cell lines when compared with the untreated cells. However, the formation of DNA laddering was only observed in the treated MCF-7 cells. Reduction of BCL-2 expression was found in the treated MCF-7 cells but BAX expression was unaltered. In conclusion, the effect of different farming systems on the proliferation of cancer cells could be cell-type-dependent but they showed no obvious differences in their effects on preventing cancer cell growth and inducing apoptosis. Practical Applications Tea is well known for its various health benefits due to its bioactivity. The findings from this study will add valuable preliminary information regarding the potential of organic and non-organic tea as natural chemopreventive and chemotherapeutic agents. These findings will provide scientific evidence on health advantages that might result from organic food consumption; thus, consumers will be able to make more informed choices.

Soil carbon dynamics estimation and dependence on farming system in a temperate climate

Maintaining or enhancing the stock of soil organic carbon (SOC) is a key factor in sustaining the soil resources of the world. The objective of this research was to study the effect of different farming systems (conventional farming with mineral fertilizers and crop specific fertilization vs. organic farming with organic fertilizers (catch crops and composted manure)) under the same 5-crop rotation (red clover, winter wheat, pea, potato, barley undersown with red clover) system on the SOC stock and the stability of SOC. The second aim was to quantify plant C inputs to the soil and to identify the relationship between C sequestration rate and C input. Data presented in this paper concerned the first rotation during 2008–2012. The main factors were farming systems: conventional and organic. Four conventional farming systems differed in the mineral nitrogen application rates used. In two organic farming systems catch crops were used with or without composted solid cattle manure. The SOC stock was determined before experiment establishment and after the first rotation. The C input into the soil was calculated based on the main product yield. The stock of SOC increased (2.57Mgha−1y−1) considerably after the first rotation only in the organic farming systems, where the total C inputs were 1368kg C ha−1y−1 higher compared to the average C inputs in conventional systems. The mineral N rate did not influence the C-input but it had an effect on the properties and mineralisation of soil organic matter. The stable C fraction of SOC proportion increased in the system in which the highest rate of mineral N (20–150kgNha−1y−1 depending on crop) was used and its proportion in the soil was comparable with the results obtained from organic farming systems. Thus, the intensive management with high N rates may benefit to a formation of more stabile SOC if the crop rotation used is properly elaborated.

Impact of farmers' practices and seed systems on the genetic structure of common sorghum varieties in Kenya and Sudan

To understand the effect of different farming systems on the dynamics of diversity of sorghum (Sorghum bicolor(L.) Moench) crop, genetic structure of widely used landraces and modern varieties collected from two contrasting agroecosystems, in eastern Sudan and western Kenya, were analysed with 16 polymorphic microsatellite markers. A total of 1104 accessions, grouped into 46 samples from individual farmers, were genotyped. Cluster analysis of the samples from the two countries displayed contrasting patterns. Most strikingly, differently named landraces from western Kenya formed widely overlapping clusters, indicating weak genetic differentiation, while those from eastern Sudan formed clearly distinguishable groups. Similarly, samples of the modern variety from Sudan displayed high homogeneity, whereas the most common modern variety from western Kenya was very heterogeneous. The high degree of fragmentation of farmlands of western Kenya, coupled with planting of different sorghum varieties in the same fields, increases the likelihood of inter-variety gene flow. This may explain the low genetic differentiation between the differently named landraces and heterogeneity of the modern variety from western Kenya. This study highlights the important role of farmers in shaping the genetic variation of their crops and provides population parameter estimates allowing forecasting of the fate of ‘modern’ germplasm (conventional or genetically modified) when introduced into subsistence farming systems.

Evaluating Yield Quality and Quantity of Garlic as Affected by Different Farming Systems and Garlic Clones

In order to study the effects of different farming systems and garlic (Allium sativum L.) clones on yield quality and quantity of garlic, an experiment was conducted with split plot arrangement with three completely randomized blockes in the 2005 growing season at the experimental research station of Shahid Beheshti University at Zirab, north of Iran. Two factors were involved in the experiment: farming systems in three levels (intensive, conventional and organic farming), as main plots and garlic clones in three levels (Atoo, Hamedani and Khorassani) as sub-plots. The studied factors in this experiment consisted of leaf number, LAI, stem height and diameter, bulb yield, weight of bulbs, number of cloves, weight of cloves and level of allicin. Results showed that the farming systems had significant effect (p<0.05) on LAI, number of plant and bulb yield, but the effect on the other factors was not significant. The highest and lowest bulb yields were obtained in intensive (9.5 ton ha(-1)) and organic (7.4 ton ha(-1)) systems, respectively. All of the top factors were significantly (p< or =0.01) affected by garlic clones. Maximum and minimum yields were obtained from Hamedani, Atoo (9.2 ton ha(-1)) and Virani (7.1 ton ha(-1)) clones, respectively. Level of allicin was not significantly affected by farming systems but, differences among garlic clones were significant. Maximum and minimum allicin yields were obtained from Hamedan (5.96 mg g(-1)) and Virani (4.52 mg g(-1)) clones, respectively. As a result, however, organic farming systems can not influence the yield in short term, but can increase it by applying crop rotation, use of organic fertilizer and cover crops in the long term.

Effects of agricultural production systems and their components on protein profiles of potato tubers

A range of studies have compared the level of nutritionally relevant compounds in crops from organic and nonorganic farming systems, but there is very limited information on the effect of farming systems and their key components on the protein composition of plants. We addressed this gap by quantifying the effects of different farming systems and key components of such systems on the protein profiles of potato tubers. Tuber samples were produced in the Nafferton factorial systems study, a group of long-term, replicated factorial field experiments designed to identify and quantify the effect of fertility management methods, crop protection practices and rotational designs used in organic, low input and conventional production systems. Protein profiles were determined by 2-DE and subsequent protein identification by HPLC-ESI-MS/MS. Principal component analysis of 2-DE data showed that only fertility management practices (organic matter vs. mineral fertiliser based) had a significant effect on protein composition. Quantitative differences were detected in 160 of the 1100 tuber proteins separated by 2-DE. Proteins identified by MS are involved in protein synthesis and turnover, carbon and energy metabolism and defence responses, suggesting that organic fertilisation leads to an increased stress response in potato tubers.

Fungi in Danish soils under organic and conventional farming

A multi-soil study was conducted in Denmark including 29 sites, 8 classified as ‘organic’, 11 as ‘conventional with manure and synthetic fertilisers’ and 10 as ‘conventional with synthetic fertilisers’. The variability of fungal abundance within the three farming systems and the long-term effects of different farming systems on fungal propagules in soil were evaluated. Fungal abundance showed large variations within all three farming systems and this variability reduced the possibility to obtain general conclusions on fungal composition in soils under different farming systems. This was illustrated by the results on total propagule numbers of filamentous fungi and yeasts. Penicillium spp. and Gliocladium roseum were more abundant under organic than conventional farming, while Trichoderma spp. were most abundant in conventionally farmed soils with synthetic fertilisers. These results were not altered after adjusting for possible differences in basic soil properties like total C and N, extractable P, CEC, base saturation and soil density. The paper discusses whether the differences in fungal abundance are characteristics of a farming system itself or associated with certain management factors being more prevalent in one farming system than the other.

Farming system-induced variability of some soil properties in a sub-humid zone of Ghana

This study assessed the effects of different farming systems, namely woodlot (WL), alley farming (AL), conventional tillage (CT) and natural fallow (NF) on the variability of organic carbon (OC) content and mean weight diameter (MWD) of a degraded Ferric Acrisol in the sub-humid zone of Ghana. The soils under woodlot accumulated the highest amount of organic carbon (18.6 g kg−1) with the least spatial variability apparently due to the greater additions of litter and minimum tillage. The conventionally tilled soil had the least OC content (13.1 g kg−1). Similar to the OC content, the woodlot soils also had the highest aggregate stability (MWD = 1.78 mm) and the least spatial variability. The stability of soil aggregates under the farming systems was greatly influenced by OC content; there was a good correlation between OC and MWD (r > 0.62**). Correlograms showed that OC and MWD are space dependent. The correlation length for OC under the different farming systems followed the order WL > NF > AL > CT, indicating that WL ensured a greater uniform distribution soil organic matter. The spatial distribution in MWD followed the same trend observed for OC. The MWD in the other farming systems was poorly related from point to point with shorter k-values, suggesting lack of uniformity due to low accumulation of OC. Generally, the woodlot system appeared to be a better, low-input restorer of soil productivity.