Lower Soil Penetration Resistance Research Articles

ROOT parameters of sugarcane and soil compaction indicators under deep strip tillage and conventional tillage

Soil tillage and agricultural traffic generate changes in soil physical attributes and affect the growth of the roots. This study evaluates the impact of system soil tillage on compaction and sugarcane root growth. The experiment was carried out on a Rhodic Kandiudox with two soil tillages (Deep Strip Tillage and Conventional Tillage) and two positions (beds or traffic lane and no traffic lane), totaling four treatments (DST-beds + no traffic lane, DST-traffic lane, CT-no traffic lane and CT-traffic lane). Soil penetration resistance (SPR), bulk density, dry mass, and root system lengths and volumes were evaluated. DST-beds presented lower values for SPR (1.45 MPa) compared to the other treatments (2.55 MPa). This lower SPR did not reflect significant increases in root growth in relation to the DST-traffic lane, meaning that the roots were not confined to the beds. The dry root mass for CT- traffic lane was 35% less than for DST- traffic lane, and CT-no traffic lane reduced of the root dry mass in the layers 0.0–0.2 and 0.2–0.4 m by 62% and 47%, respectively, compared to the DST-beds. Therefore, CT, although widely used, does not create adequate conditions for root development in the first sugarcane cycle, even in lanes with no traffic.

Soil Structural Quality and Relationships With Root Properties in Single and Integrated Farming Systems

Single farming systems (SFS) such as monocultures may negatively affect soil structural quality. This study tested the hypothesis that integrated farming systems (IFS), i.e., the combination of cropping and forestry and/or livestock farming, improves soil structural quality, root development and soil organic carbon. An experimental area was set up in 2012 at the Canguiri experimental farm belonging to the Federal University of Paraná, Southern Brazil. The soils are predominantly Ferralsols. The experimental treatments representing different farming systems, organized in a random block design with three replicates, were: Forestry (F), Conventional Crop Production (C), Livestock (L), and integrated Crop-Forestry (CF), Crop-Livestock (CL), Livestock-Forestry (LF), and Crop-Livestock-Forestry (CLF). In situ measurements and sampling were carried out in the 0–0.3 m layer during summer 2019/20, and included soil penetration resistance (PR), soil structural quality based on visual evaluation of soil structure (SqVESS scores), root length (RL), root volume (RV) and soil organic carbon content (SOC). Soil structural quality, penetration resistance, root length and volume, and SOC varied between farming systems, but no significant differences were found between single (C, L, F) and integrated farming systems (CF, CL, LF, CLF). The single system Forestry (F) and the integrated systems including forestry (LF, CF, CLF) tended to have higher SqVESS scores, i.e. poorer soil structural quality, and higher PR, which we associate with the generally drier soil conditions that are due to higher soil water uptake and higher interception and reduce the frequency of wetting-drying cycles. Roots were concentrated in the shallow soil layer (0–0.1 m depth), and this was especially pronounced in the Crop (C) single farming system. Based on the measured values, our results suggest an acceptable soil structural quality in all farming systems. Our data revealed strong, significant relationships between soil structural quality, penetration resistance, root growth and SOC, demonstrating that improvements in soil structure results in lower soil penetration resistance, higher root volumes and higher SOC, and vice versa. Soil PR was positively correlated with SqVESS (R2 = 0.84), indicating that better soil structural quality resulted in lower soil mechanical resistance. This, in turn, increased root length and volume, which increases carbon input to soil and therefore increases SOC in the long run.

Effect of Locally Made Riser Type and Operating Pressures of the Fixed Sprinkler Irrigation System on Some Soil Characteristics and Maize Yields

A field experiment was conducted during growing season of 2021, to evaluate the effect of the types of locally made riser and the operating pressures of the fixed sprinkler irrigation system on some soil characteristics and the production of maize crop at Al-Raed Research Station located in the Akkarouf area on the Abu Ghraib-Shoala Road, one km north of the highway (Baghdad - Anbar). The soil texture was silty clay loam. Two factors were used in the experiment, namely the type of risers, which included three levels: a normal riser, automatic inner tube, and automatic external tube, and the operating pressures have three levels included: 1, 1.5 and 2 bar. The following characters were studied, which are the amount of water used during the season, moisture uniformity coefficient, soil penetration resistance, and maize yield. Nested design under randomized complete block design (RCBD) was used with three replications, and the least significant difference under probability (0.05) was used to compare the averages of the treatments. The results indicates that the automatic inner and external tube outperformed the normal riser in the amount of water used during the season, which amounted to 90 m3, and also the automatic external tube outperformed in obtaining the highest moisture uniformity coefficient of 82.8% and the lowest soil penetration resistance stood 2.63 kg. cm-2, and the highest grain yield stood 6.38 tons. ha-1. As well as, the superiority of the operational pressure of 1 bar in the amount of water used during the season stood 81 m3. Season-1, and the superiority of the operational pressure of 2 bar with the highest value of the moisture uniformity coefficient amounted of 82.15%, and the lowest soil penetration resistance stood 2.67 kg. cm-2 and the highest crop yield stood 6.46 tons. ha-1. The two-way interaction between the self-propelled reed with inner tube and the operating pressure of 1 bar exceeded the minimum amount of water used during the season, which amounted to 79 m3. The two-way interaction between the automatic inner tube with the operating pressure of 1 bar outperformed with minimum amount of water used during the season, which was 79 m3 season-1. While the two-way interaction between automatic external tube and the operating pressure of 2 bars exceeded the highest value of the moisture uniformity coefficient stood 85.35%, and the lowest value of soil penetration resistance stood 2.54 kg.cm-2, and the highest crop yield stood 6.89 tons. ha-1. The results also indicate the success of using the locally designed and made "self-rising" riser according to the plant's height and used in the fixed sprinkler irrigation system to irrigate the maize crop.

Soil physical properties and soil organic carbon content in northeast Brazil: long-term tillage systems effects

ABSTRACT Concerns about the negative effects of agriculture on soil physical quality and soil organic carbon (SOC) pools have spurred on the adoption of conservation tillage systems in tropical regions. This study aimed to evaluate the long-term impacts (16th year) of conventional (CT), minimum (MT) and no-tillage (NT) practices and different cover crops (sunn hemp and a bean/millet sequence) on soil physical properties and SOC content of a corn cultivated Ultisol in the northeast of Brazil. Soil bulk density (Bd), soil penetration resistance (SPR), soil aggregation, and total aggregate-associated carbon (C) (4-2 mm) were evaluated. Tillage practices exerted strong control on soil physical properties and total aggregate-C content but were influenced by cover crop species. Minimum tillage presented the lowest Bd, irrespective of cover crop, while NT with bean/millet sequence resulted in the lowest SPR. However, as regards soil aggregation and total aggregate-C, the results indicated that there were no differences between MT and NT, with both systems presenting greater mean weight diameter (MWD) and total aggregate-C content than CT. Total aggregate-C content in the 0.00-0.05 m soil layer in conservation tillage was increased by the adoption of a bean/millet sequence. Increased mechanical disturbance through CT practices was harmful to Bd, soil aggregation and SOC accrual. Overall, more conservative tillage practices and the proper choice of cover crops might yield greater soil quality. Low intensity of soil disturbances due to the adoption of MT favors soil aggregation and the accrual of SOC in weakly structured soils through increases in contact between organic and mineral particles while not causing significant destruction of soil aggregates.

Increasing straw incorporation rates improves subsoil fertility and crop yield in the Huang-Huai-Hai Plain of China

ABSTRACT A novel deep-buried straw incorporation management was conducted to improve organic matter and over-compacted subsoil structure in Huang-Huai-Hai Plain of China. Four straw incorporation rates (CK, 0 kg ha−1; T1, 6 000 kg ha−1; T2, 12 000 kg ha−1; T3, 18 000 kg ha−1) were set up in this three-year field positioning test. It was found that soil water content (SWC), soil penetration resistance (SPR), soil organic carbon (SOC) and total nitrogen (TN) were improved with straw incorporation rate increasing. Especially in the subsoil layer, compared with CK, T3 created the highest average increase in SWC (61.3%), the lowest SPR (59.4%–39.6%) and the highest increase in SOC (25.9%) and TN (19.2%) during the three years. However, T2 had the highest average SOC conversion rate (41.1%) over the three years and the highest C:N (7.1%) in the third year. Treatments of T2 and T3 showed similar significant increases in wheat and maize yield (7% and 5%, respectively), and root biomass (approximately 19%), which were positively correlated with SWC and SOC. We concluded increasing straw incorporation rates showed more positive effects on improving subsoil SOC and structure, in which T3 had a higher SOC increase while T2 had a higher C-conversion efficiently.

Effects of strip rotary tillage with subsoiling on soil enzyme activity, soil fertility, and wheat yield

Inappropriate tillage and soil compaction threaten farmland sustainability in the Huang-Huai-Hai Plains of China. We aimed to explore the impact of plowing tillage, rotary tillage, strip rotary tillage, and strip rotary tillage coupled to a two-year subsoiling interval (STS) on soil quality at various soil depths and on wheat yield. Soil bulk density was substantially lower in the 30–45 cm depth under STS than under any other treatment, resulting in lower soil penetration resistance. Highest soil particle macro-aggregation was observed under STS in the 15–45-cm soil layer.Consistently with greater nutrient availability, key enzymes associated with soil fertility (urease, invertase, phosphatase, and catalase) showed higher activity in STS plots. Concomitantly, highest yields were recorded for STS at 10 451 and 10 074 kg/ha in 2014–2015 and 2015–2016, respectively. STS significantly improved soil physical structure and enhanced soil enzyme activity, thereby stimulating soil nutrient release and increasing winter wheat yield.

Strip rotary tillage with a two-year subsoiling interval enhances root growth and yield in wheat

Excessive tillage and soil compaction threaten the sustainable farmlands in the Huang-Huai-Hai Plains of China. Our study explores tillage practices to improve soil and root ecology and promote productivity in the winter wheat fields. We tested the impact of plowing, rotary, strip rotary tillage and strip rotary tillage with a two-year subsoiling interval (SRS) on wheat yield and root quality. SRS decreased soil bulk density compared with other treatments, resulting in lower soil penetration resistance. Root morphology and weight density decreased with the increased soil depth and was higher in SRS. Moreover, SRS increased the indoleacetic acid and trans zeatin riboside levels corresponding to greater TTC reduction activities, the total and active absorption root area. SRS increased the superoxide dismutase and catalase activities and soluble protein concentration and decreased the malondialdehyde concentration. The first two factors extracted using 11 root attributes in various soil layers through principal component analysis were selected as the integrated indicators for the minimum data set, and their integrated score was calculated to quantify the root quality. Our study suggests that SRS could significantly improve root morphology and enhance the root activity in subsoil layers, thus, delaying root senescence and increasing winter wheat yield.

Bio-intensive Modulation of Sugarcane Ratoon Rhizosphere for Enhanced Soil Health and Sugarcane Productivity Under Tropical Indian Condition

Intensive cropping and exhaustive nature sugarcane crop in tropical India have led to depletion of inherent soil fertility resulting in serious threat to sustainable sugarcane production. Improving soil organic matter and soil fertility are important factors for sustainable sugarcane production. Microbial consortia comprising of Trichoderma viride, Humicola spp, Paecilomyces lilacinus, Gluconacetobater diazotropicus, Azospiriillum brasilense, and Bacillus subtilis have great potential to recycle crop residue and restore soil fertility which eventually promote sugarcane growth. Field experiments with in situ trash management in plant crop and bio-intensive modulation of sugarcane ratoon rhizosphere in ratoon crops were conducted during 2014, 2015 and 2016 at ICAR—Sugarcane Breeding Institute, Coimbatore, Tamil Nadu, India. The results revealed that green manuring with sunnhemp, in situ trash management and application of 280:62.5:120 kg NPK ha−1 in plant crop sustained the soil health by way of reducing soil bulk density (1.26 kg dm−3), lower soil penetration resistance in the ratoon rhizosphere (1.79, 1.82 and 1.75 MPa) and higher soil organic carbon (0.52%) which in turn increased ratoon cane yield 12.24% (99.02 t ha−1) and sugar yield by 8.64% (12.83 t ha−1) over the control. Further, bio-intensive modulation of ratoon rhizosphere by off barring, trash shredding plus soil incorporation with microbial consortia and application of 350:62.5:120 kg NPK ha−1 in ratoon crop recorded significantly higher cane yield (100.95 t ha−1) and sugar yield (13.19 t ha−1) over the control. The improvement in cane yield and sugar yield to the tune of 16.35 and 14.10% due to bio-intensive modulation of ratoon rhizosphere over control have clearly established that productivity of sugarcane ratoon can be significantly improved with balanced use of fertilizers, green manuring, crop residue recycling and microbial consortia application. Similarly, bio-intensive modulation of sugarcane ratoon rhizosphere (S3) with lowest soil bulk density (1.26 kg dm−3) and soil penetration resistance values (1.69, 1.81, and 1.75 MPa) was found effective in minimising the soil compaction and improving nutrient availability (NPK) with build-up of soil microbial population than control (Trash removal). Based on the results of 3-year field experiments, it is concluded that sunnhemp green manuring and in situ sugarcane trash management coupled with application of 280:62.5:120 kg NPK ha−1 in plant crop followed by bio-intensive modulation of ratoon rhizosphere including off barring, trash shredding and soil incorporation with microbial consortia and application of 350:62.5:120 kg NPK ha−1 in ratoon crop can be recommended for sustaining soil health and sugarcane productivity under wide-row sugarcane planting systems of tropical Indian condition.

Impact of Management on the Physical Attributes of a Dystrophic Yellow Latosol

Soil use and management systems aim to create conditions that are favorable to crop growth. The hypothesis is that areas subject to intensive use of agricultural machinery and animal trampling tend to have a soil structure that is altered by aggregate fragmentation, which causes soil compaction and consequently decreases the soil’s physical and hydraulic properties. The aim of this study was to assess and compare the physical and hydraulic parameters of a dystrophic yellow latosol in an area of Cerrado in the municipality of Chapadinha, Maranhão, Brazil under different use and management systems. The following five use and management systems were studied with five replicates: native forest (control), slash-and-burn agriculture, grassland, no-till crop production and conventional tillage. Data analysis was performed using a completely randomized experimental design. The soil’s density, macroporosity, microporosity, total porosity, hydraulic conductivity, infiltration, water retention curve, penetration resistance and Soil quality assessment index (S index) were assessed for all management systems. The soil use and management systems were found to have a significant effect on the penetration resistance and the water infiltration rate. The native forest and slash-and-burn agriculture areas provided the highest soil water infiltration rates and the lowest soil penetration resistance. A multivariate analysis identified the variables associated with each soil use and management system. The slash-and-burn agriculture area had the highest S index, which means it provided soil of the best physical quality.

Production, nutrient cycling and soil compaction to grazing of grass companion cropping with corn and soybean

Agricultural management systems are needed to simultaneously enhance production, promote plant diversity, improve nutrient cycling and reduce soil compaction. We investigated the effects of intercropped forage grass on production of corn (Zea mays L.) harvested for silage at 0.20 and 0.45 m height in the summer, as well as on production of subsequent forage, soybean [Glycine max (L.) Merr.] harvested for silage, nutrient cycling and soil responses on a Typic Haplorthox in Botucatu, Sao Paulo State, Brazil. Palisade grass cv. BRS Piata [Urochloa brizantha cv. BRS Piata] was the introduced companion crop with corn (Years 1 and 2), while signal grass [Urochloa decumbens cv. Basilisk] was the residual weedy species in comparison. Guineagrass cv. Aruana [Megathyrsus maximus cv. Aruana] was the introduced companion crop with soybean (Year 3), with only a residual effect of crop systems from the previous two years. After the corn silage harvest, pasture was grazed by lambs in winter/spring using a semi-feedlot system. When cut at 0.45 m compared with 0.20 m height, corn intercropped with palisade grass had greater leaf nutrient concentration, improved agronomic characteristics, forage mass of pasture for grazing by lambs, greater surface mulch produced, and greater quantity of N, P and K returned to soil. Greater soil organic matter, P, K and Mg concentration, and base saturation in the surface soil depth and lower soil penetration resistance at all depths occurred at 0.45 m than at 0.20 m corn silage cutting height intercropped with palisade grass. Analyzing the system as a whole, harvesting corn silage crop with palisade grass intercrop at 0.45 m height was the most viable option in this integrated crop-livestock system.

Effect of Furrow Opener Design, Furrow Depth, Operating Speed on Soil Characteristics, Draft and Germination of Sugarcane

The research was conducted at ICAR-Indian Institute of Sugarcane Research, Lucknow, India, to study the effect of different types of furrow opener at different depth and speed of operation on soil penetration resistance, ridge height, specific draft, soil disturbance and germination percentage and to select the best furrow opener for establishment of sugarcane crop. The field experiment was conducted on a silt loam textured soil for three furrow openers viz. IISR furrower, IISR deep furrower and conventional type ridger operated at three average forward speed 0.26, 0.40 and 1.02 m s−1 and three average depths of 100, 150 and 250 mm. The parameters such as draft force, specific draft, soil penetration resistance, ridge height, soil disturbed and germination percentage were determined. Soil penetration resistance decreased significantly with increasing operational speeds of each furrow openers and increased significantly with depth of furrows. Soil disturbed and draft force requirements increased significantly with the increase in operation speed and depth of furrow in all the furrow openers. The significantly higher germination percentage after 30 and 45 DAP was observed with IISR deep furrow opener at 250 mm depth. The lowest soil penetration resistance, minimum specific draft and better germination were found with IISR deep furrow opener.

Production and Soil Responses to Intercropping of Forage Grasses with Corn and Soybean Silage

Agricultural management systems are needed to simultaneously enhance production, and improve soil quality. We investigated the effects of intercropped grass on production of corn (Zea mays L.) harvested for silage at 0.20 and 0.45 m height in the summer, as well as on production of subsequent forage, silage soybean [Glycine max (L.) Merr.], and soil responses on a Typic Haplorthox in Botucatu, SP, Brazil. Palisade grass [Urochloa brizantha (Hochst. ex A. Rich.) R. Webster ‘Marandu’] was the introduced companion crop with corn (Years 1 and 2), while signal grass [Urochloa decumbens (Stapf) R. Webster ‘Basilisk’] was the residual weedy species in comparison. Guinea grass [Urochloa maxima (Jacq.) R. Webster ‘Aruãna’] was the introduced companion crop with soybean (Year 3), with only a residual effect of crop systems from the previous 2 yr. When cut at 0.45 m compared with 0.20 m height, corn intercropped with palisade grass had greater leaf nutrient concentrations, agronomic characteristics, forage mass of pasture for grazing by lambs (Ovis aries), greater surface mulch produced, and greater quantity of N, P, and K returned to soil. Greater soil organic matter, P, K, and Mg concentration, and base saturation in the surface soil depth and lower soil penetration resistance at all depths occurred at 0.45 m than at 0.20 m corn silage cutting height intercropped with palisade grass. Analyzing the system as a whole, harvesting corn silage crop with palisade grass intercrop at 0.45 m height was the most viable option in this integrated crop–livestock system (ICLS).Core Ideas Agricultural management systems are needed to enhance production and improve soil quality. After corn silage harvest, pasture was grazed by lambs in winter/spring using a semi‐feedlot system. Harvesting corn silage crop with palisade grass intercrop at 0.45 m height was the most viable option.

Agro-Management Practices for Sustainable Wheat Production under Scarce Water Condition of Arid Climate

Irrigation water is vital and most limiting input in arid agriculture. This study evaluates the late sown wheat crop under various agro-management practices for enhancing the crop productivity in water scarce area. Results exhibited that better leaf water relations expressed in terms of an improvement in the leaf water potential, leaf osmotic potential, stomatal conductance and relative water content of flag leaf as well as higher rates of transpiration and net COassimilation were recorded with the planting technique of seed spreading augmented with furrows. This planting technique also expressed higher number of productive tillers, 1000grain weight and grain yield whereas lower soil penetration resistance as compared to other planting treatments. The highest water use efficiency (WUE) was achieved with the irrigation regime of 80% (evapotranspiration) ETo while in case of planting techniques, seed spreading augmented with furrows expressed the maximum values of WUE. The highest grain yield was recorded with flat sowing subjected to the irrigation equivalent to 100% reference evapotranspiration (100% ETo) which was almost similar with seed spreading augmented with furrows at 80% ETo. Under deficit irrigation regimes (80 and 60% ETo), seed spreading augmented with furrows performed better than the other two planting techniques

Effect of four different tillage practices on soil physical properties under cowpea

Cowpea (Vigna unguiculata [L.] Walp) is grown by resource poor farmers in Ghana using different tillage practices. Most of these farmers perform tillage operations without being aware of the effect of these operations on soil physical properties and crop responses. A field study was conducted during the 2009 and 2010 major crop growing seasons under rainfed conditions on sandy loam soil (Ferric Acrisol) to compare the effect of different tillage practices on some selected soil physical properties under Asontem cowpea variety. The experiment was arranged in a randomized complete block design with three replications. The treatments consisted of disc ploughing only, disc ploughing followed by disc harrowing, disc harrowing only and no tillage. Compared with the other treatments, the disc ploughing followed by disc harrowing treatment gave the most favourable soil conditions (i.e. lowest soil penetration resistance, lowest dry bulk density, highest soil moisture content, and highest total porosity). The no tillage plots produced the most unfavourable soil conditions (i.e. highest soil penetration resistance, highest dry bulk density, lowest soil moisture content, and lowest total porosity). Therefore, under the soil and weather conditions of the experiment, the best tillage practice identified for Asontem cowpea production is disc ploughing followed by disc harrowing.

Effects of ridge and conventional tillage systems on soil properties and cotton growth

Cotton (Gossypium hirsutum L.) seeds are susceptible to low temperature and excess moisture in soil during seed emergence in years with high rainfall and low temperature in spring. Therefore, a two-year field experiment was carried out to evaluate effects of ridge tillage formed in autumn (RT-I), ridge tillage formed about a month before planting (RT-II) and flat conventional tillage (CT) cultivation systems on physical properties of soil and cotton growth. The RT-I and RT-II resulted in higher soil temperature and lower soil penetration resistance than CT at all depths. The RT-II gave highest emergence, earliest maturity and greatest seed cotton yield. In conclusion, ridge tillage formed a month before planting may be considered a good agronomic practice because it can provide favorable physical conditions in soil, while also improving growth and yield of cotton under weather conditions in spring in South East Anatolia Region of Turkey.

Soybean root growth and yield in rotation with cover crops under chiseling and no-till

Compacted subsoil layers result in shallow root systems hindering the absorption of water and nutrients by plants. Disruption of soil compacted layers can be promoted by mechanical and/or biological methods, using plants with strong root systems. The immediate and medium term effects of mechanical chiseling and crop rotations on soybean root growth and yield were evaluated during four years in Brazil. Triticale (X Triticosecale Wittmack) and sunflower ( Helianthus annuus L.) were grown in the autumn–winter (April–August). In the next spring (September–October/early November), designated plots were chiseled down to 0.25 m or planted to millet ( Pennisetum glaucum L.), sorghum ( Sorghum bicolor (L.) Moench) and sunn hemp ( Crotalaria juncea L.), grown as cover crops, preceding soybean ( Glycine max (L.) Merrill). Chiseling was done only in the first year, and these plots were left fallow during the spring (September–October/early November) for the rest of the experiment. Chiseling resulted in lower soil penetration resistance and higher soybean yields in the first year. However, in the following years soybean root growth in depth was increased under rotation with triticale and pearl millet due to the presence of biopores and a decrease in soil penetration resistance. Soybean yields tended to decrease over the years in plots that were chiseled when compared with plots under crop rotation. Chiseling can be replaced by crop rotations involving species with aggressive root systems in order to alleviate deleterious effects of soil compaction on soybean yields in tropical soils. This effect is gradual, thus crop rotation will be fully effective in remediating soil compaction in a 3- to 4-year term.

Aggregation in a surface layer of a hardsetting and crusting soil as influenced by the application of amendments and grass mulch in a South African semi-arid environment

Hardsetting and crusting are forms of soil structure degradation associated with the collapse of macroaggregates during wetting and are responsible for poor seedling emergence, crop establishment and yields of food crops especially in semi-arid environments. This study investigated the effects of applying of 3.0 t ha −1 phosphogypsum, 1.0 t ha −1 polymer gel, 3.0 t ha −1 grass mulch and 5.0 t ha −1 cattle manure to the topsoil (0–15 cm) of a soil with hardsetting and crusting behavior and observed changes on aggregation under field conditions for two consecutive seasons. There were significant improvements in soil aggregate properties in the amended soil over the control. Both aggregate size distribution and wet aggregate stability showed significant differences between the amendments in the two seasons. The mean weight diameters of aggregates were 4.23 mm (mulch), 3.31 mm (manure), 2.17 mm (polymer gel), 2.23 mm (phosphogypsum) and 1.36 mm (control). The aggregates (2–4 mm) from amended soil were consistently more stable than the control and were in the order polymer gel = manure > mulch > gypsum > control. Tensile strength and bulk density of aggregates, on the other hand, were significantly higher ( P < 0.05) in the unamended than amended soil. The application of soil amendments, especially mulch, significantly increased the soil water content over the two seasons and this was associated with lower soil penetration resistance in the latter. The reduced soil strength in the amended soils contributed to higher pegging, podding and grain yields of bambara groundnut ( Vigna subterranean). This was confirmed by significantly higher correlations between soil aggregate characteristics, soil water, penetrometer resistance and growth and yield of bambara groundnut. The study concluded that significant improvements in soil aggregation can be obtained over a relatively short period and this can improve the yield of food crops.