Acid Sand Research Articles

The role of typical low vertical lattice sand barriers in regulating the airflow field on wind-eroded surfaces of photovoltaic power plants

Deserts are ideal places to build photovoltaic (PV) power plants, but this plants often face challenges from strong wind and sand activities during the operation and maintenance period, exploring the effects of PV power plant construction on wind disturbances and the control of wind and sand activities by different sand fixation measures is necessary. This study investigated the wind speed outside the PV plant, inside the plant without sand barriers measures (CK), and under three different sand-protecting barriers (gauze sand barriers (GZ), polylactic acid sand barriers (PLA), and grass grid sand barriers (GG)) inside the plant. Though calculated the surface roughness, friction velocity, wind protection effectiveness, and wind turbulence to determined the effectiveness of the barriers by these indexes comprehensively. The results show that: (1) The construction of desert PV power plant can effectively reduce the wind speed. Compared with CK, all three mechanical sand barriers within the plant reduced wind speed. Especially when the height less than 50cm, the GZ sand barriers reduced the wind speeds the most, with an average reduction rate of 101.5%. (2) All three sand barriers increased soil roughness and friction velocity within the power station. (3) At heights below 50cm, the GZ and GG sand barriers have better wind protection effectiveness than PLA sand barriers, while at hights above 100cm, the wind protection effect of PLA and GG sand barriers became less significant or even negligible (4) The wind disturbance caused by the three sand fixation measures increased with wind speed, the comprehensive performance of GZ and PLA sand barriers was superior than that of GG sand barriers and CK.

Five Years of Leaching Experiments to Evaluate Land Spreading of a Modified Bauxite Residue Before and After Treatment of Acid Mine Drainage: Sand or Soil Capping and Revegetation

The global generation of bauxite residue necessitates environmentally responsible disposal strategies. This study investigated the long-term (5-year) behavior of bauxite residue whose pH was lowered to 8.5, called modified bauxite residue (MBR), using lysimeters to test various configurations: raw MBR or used MBR (UMBR) previously applied for acid mine drainage remediation, sand or soil capping, and revegetation. Throughout the experiment and across all configurations, the pH of the leachates stabilized between 7 and 8 and their salinity decreased. Their low sodium absorption ratio (SAR) indicated minimal risk of material clogging and suitability for salt-tolerant plant growth. Leaching of potentially toxic elements, except vanadium, decreased rapidly after the first year to low levels. Leachate concentrations consistently remained below LD50 for Hyalella azteca and were at least an order of magnitude lower by the experiment’s end, except for first-year chromium. Sand capping performed poorly, while revegetation and soil capping slightly increased leaching, though these were negligible given the low final leaching levels. Revegetated MBR shows promise as a suitable and sustainable solution for managing bauxite residues, provided the pH is maintained above 6.5. This study highlights the importance of long-term assessments and appropriate management strategies for bauxite residue disposal.

Ultrahigh moisture resistance, highly sensitive and flame retardancy wearable strain sensor for agile water rescue, fire alarm and human motion detection

Smart fabrics provide considerable inspiration for the construction of wearable electronic devices due to their excellent skin affinity and breathability. However, the limited tolerance to high humidity environments and the flammable nature of fabrics impedes broader practical applications. In this paper, by an advanced and effective method, phytic acid doped (PA-) polyaniline (PANI) was polymerized in-situ on cotton fabric deposited by carbon black (CB), and then modified by non-fluorine hydrophobic particles, a flexible breathable fabric-based strain sensor (HPCF) with ultrahigh moisture resistance, flame retardancy and environmental resistance was successfully prepared. The obtained sensor shows high sensitivity (16.14 kPa−1) in the detection range of 0–2 kPa, fast response/recovery time (82/40 ms) and high cycle stability (>10,000 cycles). Thanks to its excellent hydrophobicity (WCA = 153°) and flame retardancy properties, the material enables the detection of human movement (such as finger/wrist/elbow/knee/foot movement) under a variety of harsh conditions (extremely high temperatures, underwater, acid, alkali, salt and blown sand environments). More importantly, it can be further applied to remote detection of potentially dangerous scenarios. HPCF can successfully transmit the Morse code signals of “SOS” and “HELP” sent by drowning people, and realize water rescue. In case of fire, it serves as a fire warning sensor to realize agile (1 s) fire alarming. The highly sensitive and versatile HPCF fabric sensor enables physical condition monitoring for fire and rescue personnel working in high temperature and humidity environments, which is of great value for all human activities carried out in harsh environments.

Annual bluegrass and creeping bentgrass tiller response to phosphate fertilizer and soil pH

AbstractCreeping bentgrass (CB; Agrostis stolonifera L.) grows well in low phosphorus (P) soils in monoculture, however, the soil P concentration range that provides CB an advantage over annual bluegrass (AB; Poa annua L.) in mixed swards is unknown. The objective of this research was to determine how P and soil pH influence species composition when AB and CB are established from tillers in polyculture. Replicate greenhouse experiments evaluated five P rates (0, 3, 6, 9, and 12 kg ha−1 P via triple superphosphate) and two soil pH levels (5.6 and 7.1). The highest P rate in the high pH soil resulted in the most AB cover (61%). Phosphate applied at 3 kg ha−1 P in the low pH soil provided the greatest CB cover (72%), which was fivefold greater than AB cover. All P‐receiving treatments in the low pH soil had similar green cover, but a species advantage for CB was only observed in the 3 kg ha−1 P treatment. Turfgrass quality was greatest when ≥6 kg ha−1 P was applied to low pH soil but was only slightly reduced at 3 kg ha−1 P. Regardless of pH, withholding P resulted in the lowest AB cover (<4%); however, these treatments resulted in poor turfgrass quality and low green cover (<30%). Aboveground shoot biomass increased linearly with P rate and was greater at the lower pH. In moderately acidic sand, AB was less competitive than CB when Mehlich‐3 P ranged from 4 to 6 mg kg−1.

Shallow Incorporation of Lime and Gypsum has Limited Benefit over the Sole-surface Application of Lime for Improving Grain Yield and Water Use Efficiency in the Low Rainfall Region of Western Australia

Soil acidity is one of the major soil constraints for the grain-growing industry in Australia and around the globe. While surface liming is widely adopted, it has been proven ineffective for the timely amelioration of subsoil acidity. There is a growing interest in finding alternative approaches for the effective amelioration of subsoil acidity, especially for low-rainfall regions. In a controlled environment and a field experiment, we examined whether the combined application of lime and gypsum would be more effective than lime alone under no-till (NT) and shallow strategic tillage (ST) systems for reducing the impact of soil acidity and increasing grain yield. 
 
 The controlled environment experiment highlighted that lime increased soil pH and decreased the soil exchangeable aluminium concentration (EAC) which resulted in significantly better root growth. In the field experiment, we found that the lime plus gypsum treatment, in most cases, did not significantly affect grain yield, water use efficiency (WUE) or grain quality compared to the lime treatment alone. Lime incorporation with a shallow ST was more effective in increasing soil pH and decreasing EAC at 10–20 cm depth, compared to the surface application of lime without tillage. However, ST did not affect the grain yield and WUE of wheat in 2017 and 2018 and significantly decreased the grain yield and WUE of canola in 2019 and barley in 2020. We found that measurements of either soil pH or EAC were equivalent in their ability to explain and predict the root growth of major grain crops. The results indicate that soil pH is the simplest indicator for grain growers to measure the improvement of soil acidity with liming and its impact on root growth and crop productivity. We recommend the application of lime as the preferred amendment on acidic sands, while shallow ST should be avoided in the low rainfall region. Further studies involving deep ST are warranted.

Experimental evaluation and optimization of improved conductivity of gelling acid etched fractures in deep, low-permeability reservoirs

Stimulation technology is the key to efficient development of deep low-permeability carbonate reservoirs. For such reservoirs, where the porosity and permeability are low, or where the reservoir is far from the borehole. An efficient production increase can only be achieved by using a deep percolation gelling acid fracture technique, maximizing the length of the acid etched fracture to expand the percolation area, and improving the conductivity of the acid etched fracture. A quantitative experimental study of the conductivity of acid etch fracture based on an acid rock tiling instrument, a 3D laser scanner, and an acid etch fracture conductivity evaluation device identified three typical supporting morphologies of gelling acid etch fracture walls: spot, line, and sheet. A systematic quantitative description and evaluation of the etch morphology of rocks etched by acid has been performed. The fracture morphology of acid etchings has been quantitatively evaluated under various experimental conditions such as fracture width, temperature, acid fluid consumption, displacement, and different acid fracture processes and their laws affecting fracture conductivity. The conductivity of acid corrosion fracture increases with the decrease of fracture width, and decreases with the increase of closure stress. The greater the amount of acid used, the higher the fracture conductivity; With the increase of flow Reynolds number, the conductivity of acid corrosion fracture shows a trend of increasing first and then decreasing. The fracture conductivity was compared and analyzed for different property placement conditions under the acid sand carrying technique, and the main effect of the acid etch fracture conductivity was identified. Optimization of high conductivity and deep penetration gelling acid fracturing techniques can help guide the design of acid fracturing and improve stimulation and recovery effects, thus achieving the goal of efficient development of deep, low permeability carbonate reservoirs to increase reserves and production.

Dose-response of pests to ethanedinitrile dose-response of weed seeds, soil borne pathogens, and plant-parasitic nematodes to ethanedinitrile

Ethanedinitrile is a chemical soil fumigant with promising efficacy against several key pests including weeds, nematodes, and soil-borne pathogens. The efficacy of 12 concentrations of ethanedinitrile, ranging from 8.7 to 1,751 mg kg− 1 soil, to control seeds and tubers of five weed species (Cyperus esculentus, C. rotundus, Malva parviflora, Portulaca oleracea, and Stellaria media), two nematode species (Globodera rostochiennsis and Tylenchulus semipenetrans), and four pathogenic fungal species (Fusarium oxysporum, Macrophomina phaseolina, Pythium ultimum, and Verticillium dahlia) were evaluated in acidic sand (pH: 5.6) and alkaline sandy loam (pH: 7.5–7.6), under controlled laboratory conditions. These pathogens and weeds are common in strawberry and vegetable fields and have been targeted by soil fumigants. Ethanedinitrile was injected into microcosms for 24 h. Lower doses of ethanedinitrile controlled fungal pathogens and nematodes better in acidic sand than in alkaline sandy loam. However, the reverse tended to be true for weed control as higher doses of ethanedinitrile in the acidic sand were required to control weeds than in the alkaline sandy loam. Results showed that ethanedinitrile can provide excellent control of soil-borne nematodes, pathogenic fungi, and key weed species in acidic sand and alkaline sandy loam.

Scarification in Acetic Acid, Hot Water, and Cold Sand Stratification to Improve Carob (Ceratonia Siliqua L.) Seed Germination

This study was carried out to determine the effects of acetic acid, hot water, and cold sand stratification scarification at different periods on seed germination of carob (Ceratonia siliqua L.) in Salah Alden province. The seeds were collected from Kirkuk province area on September 2016. Carob seeds stratified and not stratified treated by soaking in glacial acetic acid for 20, 40, 60, and 120 min. at lab temperature (25oC). Hot water (100oC) also used for soaking the seeds for 20, 40, 60, and 120 min. Experimental design of Randomized Complete Block Design (RCBD) with 3 replicates, and 10 seeds per each treatment per each replicate were used and the results were compared to non-treated seeds. After soaking the seeds in acetic acid and hot water, they washed thoroughly and sowed in black polyethylene grow bags. The soil used was loamy with added organic matter. After 7 months, data recorded on the germination percent and growth features including plant height, leaf area, total chlorophyll, root length, fresh and dry weight of vegetative parts, nitrogen, phosphorous, and potassium percentages in the plant. The results showed that the treatment with hot water for 60 minutes achieved the highest percent of germination (96.67%), highest leaf area 12.86 cm2, highest root dry weight (0.14 gm.), and nitrogen percent of 5.52%. The treatment for 40 minutes with hot water gave the highest fresh weight of vegetative parts was 18.6 gm. and root fresh weight (7.05 gm.). The treatment with hot water for 120 minutes achieved the highest percent of phosphorous and potassium (0.49% and 2.07% respectively).
 

Energy release rate and crack propagation rate behaviour of moisture-deteriorated epoxy adhesives through the double cantilever beam method

ABSTRACT In this study, the relationship between the energy release rate (G 1C), crack propagation rate (da/dN), and the fracture morphology of specimens with deteriorated adhesives after moisture absorption were investigated through the double cantilever beam (DCB) method. The specimens were prepared using a thermosetting epoxy adhesive based on compound carboxyl-terminated butadiene–nitrile rubber and Al 6061-T6 adherends. To accelerate the deterioration of the adhesives, open-faced specimens were immersed in water at 63°C at varying durations. Prior to the assembly of the DCB specimens, the adherends were either treated using acidic solutions or sand blasted. Consequently, the effect of the moisture deterioration of adhesive and the surface treatment performed on the adherend on the fracture morphology was studied. Furthermore, the relationship between G 1C and da/dN was systematically investigated. At a constant crack opening speed, the failure mode changed from cohesive to interfacial fracture, and then reverted back cohesive fracture as the deterioration of the specimens progressed due to increasing immersion time. Interfacial fracture was not observed for the specimens with sandblasted adherends. Lastly, a decrease in da/dN was not observed even with increasing G 1C values of the immersed specimens because interfacial fracture was easy to occur when the cyclic strains were applied.

Effect of the Biodegradable Component Addition to the Molding Sand on the Microstructure and Properties of Ductile Iron Castings.

In this work, the results of the examinations of the effect of the mold material and mold technology on the microstructure and properties of the casts parts of ductile cast iron have been presented. Four different self-hardening molding sands based on fresh silica sand from Grudzen Las, with organic binders (no-bake process), were used to prepare molds for tested castings. A novelty is the use of molding sand with a two-component binder: furfuryl resin-polycaprolactone PCL biomaterial. The molds were poured with ductile iron according to standard PN-EN 1563:2018-10. The microstructure of the experimental castings was examined on metallographic cross-sections with PN-EN ISO 945-1:2019-09 standard. Observations were made in the area at the casting/mold boundary and in a zone approximately 10 mm from the surface of the casting with a light microscope. The tensile test at room temperature was conducted according to standard PN-EN ISO 6892-1:2016-09. Circular cross-section test pieces, machined from samples taken from castings, were used. In the present experiment, it was stated that interactions between the mold material of different compositions and liquid cast iron at the stage of casting solidification led to some evolution of casting’s microstructure in the superficial layer, such as a pearlite rim observed for acidic mold sand, a ferritic rim for alkaline sand, and graphite spheroids degeneration, especially spectacular for the acidic mold with polycaprolactone (PCL) addition. These microstructural effects may point to the interference of the direct chemical interactions between liquid alloy and the components released from the mold sand, such as sulfur and oxygen. Particularly noteworthy is the observation that the use of molding sand with furfuryl resin with the addition of biodegradable PCL material does not lead to an unfavorable modification of the mechanical properties in the casting. The samples taken from Casting No. 2, made on the acidic molding sand with the participation of biodegradable material, had an average strength of 672 MPa, the highest average strength UTS-among all tested molding sands. However, the elongation after fracture was 48% lower compared to the reference samples from Casting No. 1 from the sand without the addition of PCL.

Short-Term Decomposition and Nutrient-Supplying Ability of Sewage Sludge Digestate, Digestate Compost, and Vermicompost on Acidic Sandy and Calcareous Loamy Soils

Organic waste and the compost and vermicompost derived from it may have different agronomic values, but little work is available on this aspect of sewage sludge. A 75-day pot experiment with perennial ryegrass (Lolium perenne) as the test plant aimed to investigate the fertiliser value and organic matter replenishment capacity of digested sewage sludge (DS) and the compost (COM) and vermicompost (VC) made from it, applied in 1% and 3% doses on acidic sand and calcareous loam. The NPK content and availability, changes in organic carbon content and plant biomass, and the efficiency of the amendments as nitrogen fertilisers were investigated. The final average residual carbon content for DS, COM, and VC was 35 ± 34, 85 ± 46, and 55 ± 46%, respectively. The organic carbon mineralisation rate depended on the soil type. The additives induced significant N mineralisation in both soils: the average increment in mineral N content was 1.7 times the total added N on acidic sand and 4.2 times it on calcareous loam for the 1% dose. The agronomic efficiency of COM and VC as fertilisers was lower than that of DS. In the short term, DS proved to be the best fertiliser, while COM was the best for organic matter replenishment.

Response of Some Improved Upland Rice Varieties to Different Sources and Rates of Nitrogen Fertilizer in A Humid Rain Forest Region

ABSTRACT
 Nitrogen (N) is a major lacking nutrient element for the growth and yield of cereal crops Calabar, it is necessary to determine the response different sources and rates of N in four varieties of upland rice. Treatments comprised factorial combinations of the four rice varieties (NERICA 1, NERICA 2, FARO 45, FARO 48), three straight inorganic N sources (urea, Calcium ammonium nitrate, ammonium sulphate) and four levels of N (0, 30, 60, 90 kg N ha-1) laid in randomized complete block design. The N was split applied twice; one-third at the beginning of tillering and the remainder at panicle initiation. The results showed that the source of fertilizer N did not affect significantly the growth and yield of the rice crop (p=0.05). Considering that soils in Calabar are acid sands it will not be advisable to consistently apply such acidifying fertilizers as ammonium sulphate or urea except with soil liming which will undoubtedly increase the cost of production and probably make it unprofitable to cultivate rice in the area. The fertilized crop grew taller and produced more biomass compared with the control. It also produced significantly more tillers hill-1, panicles m-2, grains panicle-1, weight of 1,000 grains and grain yield. However, whereas NERICA 1, NERICA 2 and FARO 45 were more responsive to lower N levels, the grain yield of FARO 48 was significantly higher when the crop received 90 kg N ha-1 compared with other varieties, probably because of its longer growth duration in the field. The responsiveness of these varieties to low N application was the result of their higher grain yield resulting from enhanced N use efficiency. Genotypes that were most responsive to low N input levels were early maturing with high N-use efficiencies. On the basis of grain yield, it is recommended that for high yield in the humid region of Cross River State, N should be applied at the rate of 60 kg ha-1 for early- and 90 kg ha-1 or above for the medium-maturing upland rice varieties.
 Keywords: Rice, Varieties, Growth and Yield

The composition, geography, biology and assembly of the coastal flora of the Cape Floristic Region.

The Cape Floristic Region (CFR) is globally recognized as a hotspot of plant diversity and endemism. Much of this diversity stems from radiations associated with infertile acid sands derived from sandstones of the geologically ancient Cape Fold Belt. These ancient montane floras acted as the source for most subsequent radiations on the Cape lowlands during the Oligocene (on silcretes) and Mio–Pliocene (on shales). The geomorphic evolution of the CFR during the Plio–Pleistocene led to the first large-scale occurrence of calcareous substrata (coastal dunes and calcarenites) along the Cape coast, providing novel habitats for plant colonization and ensuing evolution of the Cape coastal flora—the most recent diversification event in the Cape. Few studies have investigated the CFR’s dune and calcarenite floras, and fewer still have done so in an evolutionary context. Here, we present a unified flora of these coastal calcareous habitats of the CFR and analyze the taxonomic, biological and geographical traits of its component species to gain insights into its assembly. The Cape coastal flora, comprising 1,365 species, is taxonomically dominated by the Asteraceae, Fabaceae and Iridaceae, with Erica, Aspalathus and Agathosma being the most speciose genera. In terms of growth-form mix, there is a roughly equal split between herbaceous and woody species, the former dominated by geophytes and forbs, the latter by dwarf and low shrubs. Species associated with the Fynbos biome constitute the bulk of the flora, while the Subtropical Thicket and Wetland biomes also house a substantial number of species. The Cape coastal flora is a distinctly southern African assemblage, with 61% of species belonging to southern African lineages (including 35% of species with Cape affinity) and 59% being endemic to the CFR. Unique among floras from the Cape and coastal Mediterranean-climate regions is the relatively high proportion of species associated with tropical lineages, several of which are restricted to calcareous substrata of the CFR. The endemic, calcicolous component of the flora, constituting 40% of species, represents 6% of the Cape’s regional plant diversity—high tallies compared to other biodiversity hotspots. Most coastal-flora endemics emerged during the Plio–Pleistocene as a product of ecological speciation upon the colonization of calcareous substrata, with the calcifugous fynbos floras of montane acid substrata being the most significant source of this diversification, especially on the typically shallow soils of calcarenite landscapes. On the other hand, renosterveld floras, associated with edaphically benign soils that are widespread on the CFR lowlands, have not been a major source of lineages to the coastal flora. Our findings suggest that, over and above the strong pH gradient that exists on calcareous substrata, soil depth and texture may act as important edaphic filters to incorporating lineages from floras on juxtaposed substrata in the CFR.

Performance and Dry Matter Accumulation of Groundnut in an Ultisol Amended with Phosphorus and Lime.

&lt;b&gt;Background and Objective:&lt;/b&gt; Adequate yield improvement in groundnut may not be achieved in acid sand Ultisol through the application of mineral phosphorus alone, however, a combined application of lime and phosphorus fertilizer may be a better management option in such soils. Hence, this study evaluated the effects of four levels of lime (0, 2.0, 4.0 and 8.0 t ha&lt;sup&gt;1&lt;/sup&gt;) and four phosphorus (P) levels (0, 25, 50 and 75 kg ha&lt;sup&gt;1&lt;/sup&gt;) on the performance of groundnut (&lt;i&gt;Arachis hypogaea &lt;/i&gt;L.) in the humid rainforest of South Eastern Nigeria. &lt;b&gt;Materials and Methods:&lt;/b&gt; The study was a factorial experiment laid out in a Randomized Complete Block Design (RCBD) and consisted of sixteen treatment combinations replicated three times each. &lt;b&gt;Results:&lt;/b&gt; The result obtained showed that the application of phosphorus fertilizer and lime had a significant (p<0.05) effect on plant height, number of leaves per plant, number of branches per plant, 75 kg ha&lt;sup&gt;1&lt;/sup&gt; P and 8.0 t ha&lt;sup&gt;1&lt;/sup&gt; lime resulted in the highest growth parameter. Similarly, 75 kg ha&lt;sup&gt;1&lt;/sup&gt; P and 8.0 t ha&lt;sup&gt;1&lt;/sup&gt; lime significantly improved the number of pods per plant 30.67, pod yield 3.58 t ha&lt;sup&gt;1&lt;/sup&gt;, biomass yield of 4.68 t ha&lt;sup&gt;1&lt;/sup&gt;, seed yield of 2.1 t ha&lt;sup&gt;1&lt;/sup&gt; and 100 seed weight of 44.58 g, seed yield of groundnut while curtailing the number of unfilled pods 2.33. &lt;b&gt;Conclusion:&lt;/b&gt; Application of phosphorus and lime at 75 kg ha&lt;sup&gt;1&lt;/sup&gt; P and 8.0 t ha&lt;sup&gt;1&lt;/sup&gt; lime is a beneficial agronomic practice that could enhance the productivity of groundnut in the Calabar rainforest zone of Cross River State.

Low-cost and scalable preparation of nano-Si from photovoltaic waste silicon for high-performance Li-ion battery anode

Nano silicon (nano-Si)-based materials have been considered as promising anodes for next-generation Li-ion batteries (LIBs) because of their high specific capacity. However, a facile processing method of nano-Si with cheap Si sources is still lacking. Herein, we propose a facile, scalable and cost-effective route to produce nano-Si using a low-cost Si source from photovoltaic (PV) waste silicon. The nano-Si of 484 nm in [Formula: see text] can be easily produced using the PV waste Si by facile acid washing, heat treatment and sand milling steps. Compared with commercial nano-Si (120 nm), our low-cost nano-Si exhibits higher Coulombic efficiency (87.1%) and better cycling stability. The cycling stability of nano-Si can be obviously enhanced by using a carboxymethyl cellulose (CMC) binder and an electrolyte composed of 1 mol L[Formula: see text] LiPF6 in fluoroethylene carbonate (FEC), ethyl methyl carbonate (EMC), and dimethyl carbonate (DMC) (1:1:1). The nano-Si with CMC binder in 1 mol L[Formula: see text] LiPF6 FEC/EMC/DMC electrolyte could maintain a discharge capacity of 1488 mAh g[Formula: see text] after 200 cycles at 1 A g[Formula: see text]. Our work provides a promising, sustainable method to make high-performance nano-Si using a low-cost Si source.

Response of Soil pH and Nodulation of Three Chickpea Genotypes to Biochar and Rhizobium Inoculation

ABSTRACT Soils in the semi-arid regions such as north-eastern South Africa, where chickpea was recently introduced, are commonly characterized by poor fertility and low pH. Preliminary studies show that the crop has a huge potential in the region, but lack of nodulation has consistently been a problem. We assessed the response of soil pH and nodulation of three chickpea genotypes (ACC #4, ACC #5, and ACC #6) to biochar application (0, 10, and 20 t ha−1) and rhizobium inoculation (inoculated and uninoculated) in Thohoyandou (clay soil) and Nelspruit (loamy sand soil), South Africa in 2015 and 2016. Nodulation was assessed at flowering by determining the number of nodules per plant and nodule dry weight, and soil pH was analyzed after harvest in both seasons. Biochar increased pH by 0.7 (clay soils) and 0.7–0.8 (the more acidic loamy sand soils) pH units. Similarly, biochar increased nodulation in inoculated treatments in both locations and seasons, and this was mainly associated with the effect of biochar on soil pH. The increase in nodulation with inoculation varied amongst the genotypes. Clearly biochar and rhizobium inoculation may be crucial for improving soil pH and nodulation in chickpea cropping systems characterized by poor soils.

First year woody survival supports feasibility of forest-steppe reconstruction as an alternative to landscaping in industrial areas

Urban-industrial restoration of complex native vegetation, such as grassland-forest mosaics could counteract land degradation and help develop methodology for larger scale complex restorations. We have studied the impact of grassland reconstruction techniques, the resulting biotic conditions, plus abiotic conditions on early woody survival in a forest-steppe reconstruction at an urban-industrial site. The study area is situated at the factory of the LEGO Group, Nyíregyháza in the acidic inland sand dune region of Nyírség, NE Hungary, Europe. Over 10,000 undercut 1-2-year-old saplings of 16 tree and shrub species were planted in patches of various size in November 2015 at ca. 20% of the restoration area. Specific plans were developed for each woody patch within the restored grassland. Tree and shrub survival was counted for all saplings in all patches in the summer of 2016. Vegetation height, cover of herb-layer, and elevation a.m.s.l. were estimated for each woody patch and soils were characterized for each restoration parcel. First year woody survival rates ranged between 4 and 66% for the different species. Only vegetation height had an overall negative impact on woody survival and seven species reflected some (often contradictory) impacts of the studied environmental variables. In our interpretation this shows that woody survival was basically independent of the grassland reconstruction techniques, but also that the management of the herb-layer of new woody plantations can be crucial in long-term maintenance. Our results support that the reconstruction of complex native habitats with a park-like appearance is a viable alternative to landscaping in industrial areas that can counteract land degradation and increase green infrastructure connectivity. The methods applied can be transferred to larger-scale restoration with modifications.

Effects of Cattle-Cud Digester on Soil Properties and Yield of Sweet Potato on Acid Sand of Akwa Ibom State, Nigeria

Effects of Cattle-Cud Digester on Soil Properties and Yield of Sweet Potato on Acid Sand of Akwa Ibom State, Nigeria

Effects of Cattle-Cud Digester on Soil Properties and Yield of Sweet Potato on Acid Sand of Akwa Ibom State, Nigeria

Holistic management of arable soil is key to dealing with the most complex [1], dynamic, and interrelated soil properties, thereby maintaining sustainable agricultural...

Fertility Index and Microbial Population of Acid Sand Receiving Cassava Mill Effluent in of Uyo, Nigeria

A study was conducted to examine the changes in fertility and microbial indices of acid sand, under cassava effluent discharge at varying periods. Three cassava mill sites at Uyo discharging cassava effluent within three periods: less than 5 years discharge, 10 years discharge and 15 years discharges were used. Adjacent plots to each of the sites served as control. Soil samples were collected on the surface along the discharge strides in the morning, afternoon and evening. Measured soil nutrients were fitted into fertility index to determine the fertility status while total bacterial count, total fungal count for mold were the parameters used to assed the microbial count as influenced by cassava mill effluent discharge. Data were analyzed using descriptive statistics and analysis of variance at 5% probability level. Soil fertility index was greater in discharge site of 15 years (25) compared to 10 years (10), less than 5 years (7) and control (12). Total bacterial count was significantly high in site with 15 years discharge period (6.36cfug-1) compared to 10 years (2.88cfug-1), less than 5 years (2.72cfug-1) and control (3.83cfug-1). Total fungal count for mold was significantly high in site with 15 years discharge period (4.32cfug-1) compared to 10 years (3.27cfug-1), less than 5 years (2.18cfug-1) and control (3.77cfug-1). Calcium was significantly highest at noon (4.7cmol.kg-1) under less than 5 years period and in the morning (5.1cmol.kg-1) at site with 10 years period of discharge whereas Ca was highest in the evening (6.00 cmol.kg-1) in location that received effluent for 15 years. High soil fertility due to increase in population of microbes status was seen in the site receiving effluent for 15 years compared to other periods.