Development and Implementation of an Automatic Plant Watering System

The application of biochar is promising for improving the physical, chemical and hydrological properties of soil. However, there are few studies regarding the influence of biochar particle size. This study was conducted to evaluate the effect of biochar size on the physical, chemical and hydrological properties in sandy and loamy tropical soils. For this purpose, an incubation experiment was conducted in the laboratory with eight treatments (control (only soil), two soils (loamy and sandy soil), and three biochar sizes (<0.15 mm; 0.15–2 mm and >2 mm)). Analyses of water content, bulk density, total porosity, pore size distribution, total carbon (TC) and total N (TN) were performed after 1 year of soil–biochar-interactions in the laboratory. The smaller particle size <0.15 mm increased water retention in both soils, particularly in the loamy soil. Bulk density slightly decreased, especially in the loamy soil when biochar > 2 mm and in the sandy soil with the addition of 0.15–2 mm biochar. Porosity increased in both soils with the addition of biochar in the range of 0.15–2 mm. Smaller biochar particles shifted pore size distribution to increased macro and mesoporosity in both soils. Total carbon content increased mainly in sandy soil compared to control treatment; the highest carbon amount was obtained in the biochar size 0.15–2 mm in loamy soil and <0.15 mm in sandy soil, while the TN content and C:N ratio increased slightly with a reduction of the biochar particle size in both soils. These results demonstrate that biochar particle size is crucial for water retention, water availability, pore size distribution, and C sequestration.

Artemisia annua L. produce an array of complex secondary plant metabolite including artemisinin (ART), which kills the principal malarial parasite, Plasmodium falciparum, a compound of current interest in the treatments of drug resistant malaria. However, this compound remain expensive and hardy available on global scale. Synthesis of ART has been proved to be economically impossible. Therefore, increase in yield of natural occurring ART is necessary. The study evaluated the influence of soil types on germination, growth and artemisinin content of A. annua of Chen Young variety in Sokoto agro ecological region of Nigeria and. A greenhouse experiment was conducted in 2017 at Botanical garden of Usmanu Danfodiyo University Sokoto. The seeds were sown in plastic pots containing clay, sandy and loamy soils in completely randomized design with 4 replications. Germination percentage (G), Mean germination time (MT), Coefficient of variation of the germination time (CVt), Mean germination rate (MR), Uncertainty of germination (U) and Synchrony of germination (Z) were evaluated. Growth parameter and Artemisinin content were also determined. ART was determined and quantified with high performance liquid chromatography (HPLC) using calibration curve constructed by plotting the peak area against the concentration (5, 10, 15, 20, 25 µg/ml) of ART standard solutions. The results revealed that soil types had no significant effect on germination and growth parameters evaluated (P<0.05). However, clay had the highest G, MT and CVt than sandy and loamy soils. The highest speed of germination per day was observed on sandy soil. Clay soil had the least values of U (2.277±0.2 bit) while the degree of overlapping germination was frequent in the clay (Z). The result obtained shows that treatment had no significant effect on the growth parameters evaluated (P<0.05). Artemisinin content was significantly affected by soil type with the higher content in sandy soil (37.73 µg/ml) follow by clay and loamy soils with 17.90 and 15.70 µg/ml respectively. This study concludes that A. annua seeds can germinate and survived on different soils type in Savanna region of Nigeria. The study suggested the use of sandy soil in cultivation of the plant for its influence on high artemisinin content.

The use of nitrification inhibitors (NIs; dicyandiamide - DCD) is an alternative to reduce oxidation of ammonium (NH4+-N) to nitrate (NO3–-N) in the soil, reducing NO3–-N losses from fertilization practices. Based on the hypothesis that DCD reduces conversion of NH4+-N to NO3–-N in tropical soils and inhibits ammonia oxidizing microorganisms (AOM) abundance, soils from the Piracicaba region, São Paulo, with different textures (sand, loam and clay) were incubated with ammonium sulphate (AS) and DCD. Contents of NH4+-N, NO3–-N, soil pH, and AOM abundance were quantified periodically. Ammonium sulphate increased AOM abundance in all soils, but AS+DCD presented AOM abundances similar to the control. During 90 days of incubation, the effectiveness of DCD in reducing NO3–-N production was 1.8, 86.4, and 145.6 mg kg–1, while the effectiveness of DCD in reducing AOM abundance was 1.2, 3.0 and 2.3 × 10–3 g soil–1 for sandy, loamy, and clayey soils, respectively. DCD effectiveness was greater in loamy and clayey soils due to the naturally low nitrification in sandy soils. Application of AS treated with DCD showed potential not only to reduce NO3–-N production in loamy and clayey soils, but also to decrease the soil nitrification rate. Overall, DCD was effective in reducing AOM abundance and conversion of NH4+-N to NO3–-N in loamy and clay soils evaluated here. The increase in clay content directly influences DCD effectiveness in reducing conversion of NH4+-N to NO3–-N.

Fabrication of carboxymethyl tamarind kernel gum-based hydrogel and its applicability in different types of soils for agronomy

The long-term transformation of organic matter in agroecosystems is modulated by soil properties and functional traits of plants and microorganisms, and is an indicator of soil quality. We studied how contrasting soil texture (loamy vs sandy) and two plant genotypes (a wild type, WT and a mutant deficient in root hairs, rth3) altered organic matter through microbial functioning in a field experiment after 5 years of maize monoculture. Our hypotheses were that (1) loamy rather than sandy soil will promote a larger OM storage; and (2) root-hairs, entailing a higher root-soil interface and water retention in the rhizosphere, boosting microbial processes and OM fluxes, will increase OM content not only in the rhizosphere but in the long-term, also in the bulk soil. To address these hypotheses, plots were filled with homogenized soil, being sandy soil a mix of 16.7 % loam with quartz sand, and the two maize genotypes. After 5 years of monoculture, soil was collected at the early maize growth stage of BBCH19, in the first 20 cm and the 20 to 40 cm depths. We determined stoichiometric ratios of total (TOC/TN) and labile (DOC/DON) fractions of soil organic matter, and microbial eco-physiological indexes related to OM transformation and sustainability, i.e. respiration-to-biomass ratio, qCO2, and microbial-to-total organic C ratio, Cmic:Corg.  The 5- and 7-times larger C supply in loamy vs sandy soil, for WT and rth3, respectively was explained by 40% more efficient C metabolism, i.e. less C losses through respiration per biomass unit, by 90% lower specific labile C content (DOC:Cmic ratio) and by 60% faster microbial turnover (µmax-1) in the former. As the TN content was only 3.1 and 4.2 times larger in loamy than sandy soil for WT and rth3 respectively, the resulting C:N ratio was 1.7- times greater for loamy than sandy soil, indicating more unbalanced stoichiometry in the former for both genotypes. Remarkably, the C and N content increased 20 and 36 %, respectively, after 5 years of maize monoculture, in the plots under root hair-deficient mutant than under wild type maize resulting in significantly larger C storage at rth3-plots in loamy soil. This may be explained by the reported higher exudates production by rth3 under the field conditions. Soil depth up to 40 cm did not show big differences in the capacity for C storage, likely due to similar root density in both depths. Concluding, loamy soil showed a higher capacity of C storage through microbial turnover and sandy soil demonstrated larger C losses through DOC compounds and respiration after 5 years of maize monoculture. Finally, carbon availability was not the limiting factor in sandy soil for microbial growth, but rather other factors such as soil water holding capacity, or OM fluxes from rhizosphere to bulk soil.

Pochonia chlamydosporia applied via seed treatment for nematode control in two soil types

O silício tem sido muito utilizado na agricultura brasileira, especialmente após sua inclusão na legislação de fertilizantes e corretivos. Poucos são os estudos, no entanto, sobre sua solubilidade em solos tropicais, que é importante para sua utilização. Foi avaliado silício solúvel de solos de cerrado muito argilosos (LVd, LVAd, NVef), de textura média (PVAe, LVd, LVAd) e arenoso (RQo) incubados com calcário (0, 2, 4 e 6 Mg ha-1) e ácido silícico (0 e 400 mg kg-1Si) e quatro repetições. As amostras dos solos foram secas, passadas em peneira ABNT 50 (0.297 mm) acondicionadas em potes (250 g) com os tratamentos e incubados por 90 dias (80 % da capacidade de campo). O ácido acético 0,5 mol L-1(AA) extraiu mais silício em relação à água (A) e CaCl2 0,01 mol L-1(CC). Os teores de Si foram maiores nos solos muito argilosos seguidos daqueles de textura média e arenoso e maiores no horizonte B que no horizonte A dos latossolos. Houve efeito apenas das doses de calcário que reduziram a acidez potencial, aumentaram o pH (CaCl2) e os teores de Ca e silício extraível em AA para todos os solos. Houve aumento nos teres de silício extraível por CC e A nos solos de textura média e arenoso e diminuição nos solos muito argilosos por efeito da calagem. Verifica-se a necessidade de estudos com plantas para seleção de extratores adequados para avaliar a disponibilidade de silício, especialmente em solos oxídicos, onde o aumento de pH tem efeito negativo sobre a solubilidade de silício.

The results of studies on the effect of density, fertilizer and soil type on miscanthus productivity in Western Polesie are presented. It was found that the average yield of dry biomass of 15.5 t/ha was obtained on a dark gray loamy soil for a planting density of 20 pc/ha., and fertilizer application at the rate of N60Р200К200. The application of mineral fertilizers (N60Р200К200) on dark gray light-loamy and sod-podzolic sandy-sandy soil provided the highest increase in dry mass yield (up to control) of 2.9–3.4 t/ha. As the results of research have shown, the dry matter yield varies significantly under the influence of certain factors. Thus, in four years on average the highest dry matter yield was obtained on condition of planting density of 20 thousand pcs./ha and application of N60P200K200 on both dark gray light loamy soil and sod-podzolic sandy soil, 15.5 and 13.1 t/ha respectively. The lowest yields on two types of soils were obtained on condition of planting density of 10 thousand pcs./ha in the trial field without fertilizers (check) – 12.0 t/ha and 9.1 t/ha on dark gray loamy and sod-podzolic light sandy soils, respectively. The application of mineral fertilizers at the rate of N60P100K100 ensured increase in the yield by 1.8 and 2.2 t/ha of dry mass on two types of soils. Increasing the dose of phosphorus and potassium fertilizers up to 200 kg. d. r./ha contributed to an increase in the amount of dry mass to 15.0 and 10.1 t/ha compared to the trial field without fertilizers. The results of the research confirm the fact that with the increase in grain planting density and application of mineral fertilizers, the yield of miscanthus biomass increases, thus, the yield of solid fuel and energy increases as well. Consequently, the highest fuel yield of 17.1 t/ha with the energy yield of 271 GJ/ha was ensured by the application of mineral fertilizers at the rate of N60P200K200 and an increase in planting density to 20 thousand pcs./ha on dark gray light loamy soil. The lowest productivity at this density was characterized by the option without fertilizers (check) - 12.2 t/ha of dry biofuel and 194 GJ/ha of energy. Planting miscanthus plantations with the density of 15 thousand pcs./ha for four years on average reduced the yield of biofuel to 11.0 t/ha and energy to 175 GJ/ha in the trial field without fertilizers (check). However, the lowest amount of biofuel of 10.1 t/ha and energy yield of 159 GJ/ha was obtained in the trial field without fertilizers at the planting density of miscanthus of 10 thousand pcs./ha. The application of mineral fertilizers at the rate of N60P100K100 and N60P200K200 contributed to the increase of the above indices to 13.5 and 14.7 t/ha of dry biofuel and 215 and 235 GJ/ha of energy, respectively. Keywords: miscanthus, dry biomass, solid biofuels, energy, soil.

Winter wheat was grown over 2 years (1995, 1996) in an organic and integrated cropping system on sandy and loamy soils. Root growth was measured on five to six occasions each year with an auger sampling procedure and the ingrowth core method. The first resulted in an estimate of net root development, while the latter revealed gross root growth (GG) or root production. Total root production was about 80–150 km m–2 (0- to 30-cm soil layer) between April and July and exceeded the net size of the root system at harvest by a factor of between 2 and 4. The C input into the soil could be estimated as 1.4–2.6 t ha–1 by this root production. The cropping systems had nearly no influence on root production. The largest differences occurred between the years. The net root length tended to be lower on sandy soils compared to the loam, but total root production was higher. Root mortality, which is the difference between GG and net root growth, was also higher on sandy soils. The turnover index, which is the mean of the relative root production rates and relative root mortality rates, was positively related to the soil sand content in both years.

Previous studies found that a small DC electrical current could attract anions to the anode in sandy soil, even with solute flow towards the cathode. Laboratory experiments were conducted in a vertical, partially saturated column with different soils to determine if nitrate transport could similarly be controlled using electrokinetic (EK) technology. Nitrate concentration, pH value, electrical potential difference, and soil water content were measured for three soils at selected times at different distances from the anode. Constant electrical current was applied to the system for 9 h, and measurements continued for a total of 48 h. The results demonstrated that nitrate can be strongly retained near the anode against gravity in sandy soil with an 80 mA (0.5 mA/cm2) current input. When the percentage of clay in the soil was increased, the EK effect on ion movement decreased; the transport of both ions and water were inhibited by fine clay particles. The loamy soil showed a slight increase in nitrate concentration near the anode, but the clayey soil showed no change. An increase in pH near the cathode was seen in all soils. Water content for sandy soil was higher at the bottom of the column and lower at the top of the column, but for loam and clay soils, the lowest water content was found above the cathode near the bottom of the column. Electrical potential difference between the two electrodes showed that the sandy soil required the highest electrical potential difference to obtain the desired current level; loamy and clayey soils required less. For sandy soil, the highest potential difference was found near the top of the column, but for loam and clay soils, the highest electrical potential difference was measured near the bottom, next to the cathode, suggesting that these locations were the critical zones limiting electrical ion transport.

Loamy soils, characterized by a balanced mixture of sand, silt, and clay, offer high agricultural productivity and geotechnical applications. These soils exhibit medium water infiltration, aeration, and erosion, with high moisture and nutrient retention. They are less prone to flooding and disintegration compared to more clayey or sandy soils, owing to their balanced texture and optimal moisture retention. The effective stress principle, established by Terzaghi, explains the soil's behavior under different drainage conditions, with loamy soils showing moderate firmness when dry and cohesive properties when wet. This research aims to study the shear strength of loamy soils. CIU triaxial tests provided friction angles (ϕ') between 30° and 32° and cohesions (C') of 16 to 18 kPa, while direct shear tests yielded friction angles of 24.3° to 26.7° and cohesions of 22.7 to 36.1 kPa. Geotechnical characterization identified the soil as Silty Loam with high plasticity, containing kaolinite, quartz, and smectite. Overall, loamy soils exhibit complex behavior influenced by their texture, moisture, and compaction conditions, with significant implications for geotechnical applications and soil stabilization practices.

Plants need water to grow well, so watering must follow the plant's needs. Parameters that affect the process of watering plants are air temperature and soil moisture, thus, we need a control system that can make decisions in the form of watering time to meet plant water needs according to their needs, namely an automatic watering system. Fuzzy method can be used for human-like decision making in a control system. This study uses the Sugeno fuzzy method which is integrated into the Microcontroller as the controller. Testing of this system is carried out on eggplant plants which are regulated based on how long the watering time is so that the air temperature and soil moisture are following the plant's needs. The test resulted that the effective watering time interval so that the eggplant soil moisture was maintained at 40-60% was 21 seconds. It can be concluded that the fuzzy inference embedded in the design has been able to overcome the problem of watering eggplant plants, where the test shows that after the watering process, the soil moisture value can be maintained at an average value of 55% so that the soil moisture is following the needs of the plant.

Soil type affects plant colonization, activity and catabolic gene expression of inoculated bacterial strains during phytoremediation of diesel

A correlation for cyclic degradation of natural clayey and sandy soils at different strain amplitudes

Work in this paper evaluates the effectiveness of soil treatment with lime and fly ash in terms of response with permeability and void ratio. The laboratory investigations were carried out on low plastic illite clay and poorly graded sand. Three different lime and fly ash contents (1%, 3%, and 5%) were considered for treatment purpose. After mixing soil with additives, a reaction period ranging from 3 to 14 days was allowed for the bond development between lime and fly ash with soil particles. From test results, it is found that plasticity indices decrease for clayey soil by adding both lime and fly ash. The reduction of the coefficient of permeability due to treatment with lime and fly ash is higher for clay than for sand. Permeability of the lime and fly ash treated clayey soil decreases subsequently up to 58–92% and 68–95% during a reaction period of 14 days. For sandy soil, under similar testing conditions, this reduction is 30–84% and 55–95% for lime and fly ash treated soil, respectively. The change in void ratio pattern with additives illustrates that sandy soil shows better formation with lime than fly ash, whereas clayey soil interacts better with fly ash than that of lime. Fly ash is found more effective than lime in decreasing the permeability of clayey and sandy soils (5–30%). The results indicate that the selected additives are effective for stabilizing both the low plastic clay and poorly graded sandy soil to utilize these soils as cladding materials for water bodies.