Natural Soil Amendment Research Articles

Natural Soil Amendments to Reduce Nitrate Leaching in Potato Production

Natural Soil Amendments to Reduce Nitrate Leaching in Potato Production

Green tuff supplementation improves plant growth and microbial interactions of soil aggregates and rhizosphere in cherry tomato (Solanum lycopersicum L. var. cerasiforme) cultivation

Soil and rhizosphere microorganisms play essential roles in nutrient cycling and plant growth promotion in agricultural systems. Natural mineral materials, such as zeolite, are widely used as soil amendment materials to create “healthy” conditions for microorganisms related to plant cultivation. However, the effects of these minerals on microbial community structures in the soil with different aggregate scales and rhizosphere are largely unknown. In this study, we used cherry tomato (Solanum lycopersicum L. var. cerasiforme) cultivation experiment fed with 80 kg/1000 m2 green tuff (GT) as a natural soil amendment material and without GT (control blank as conventional farming; CK). The total yield and average root weight in GT were 1.2-fold and 1.6-fold higher than those in CK, respectively. The 16S rRNA gene amplicon sequence analysis in size-fractionated soil samples showed that the genus Bacillus, known as plant growth-promoting bacteria (PGPB), was significantly increased in bulk soil (nonfractionated soil), large macroaggregates (LMA, 5.6 mm–1 mm diameter), and small macroaggregates (SMA, 1 mm–250 μm diameter) in GT, and the genus Nocardioides, known as PGPB, was significantly increased in the rhizosphere of GT compared with CK (p < 0.05). These microorganisms had significant positive correlations with several PGPB, such as Bacillus, Nocardioidaceae, and Mesorhizobium. These results suggest that green tuff supplementation improves the microbial interactions in the soils, yields and root weight of cherry tomato.

Potential of biofertilizers and natural soil amendments to mitigate heavy metal contents of soil in lowland rice (Oryza sativa L.) farming

Potential of biofertilizers and natural soil amendments to mitigate heavy metal contents of soil in lowland rice (Oryza sativa L.) farming

Recovery of waste nutrients by duckweed for reuse in sustainable agriculture: Second-year results of a field pilot study with sorghum

Between 62% and 92% of industrial and municipal wastewater in upper-middle, low-middle, and low income countries is discharged to the environment untreated, releasing valuable nutrients such as nitrogen (N) and phosphorus (P) into rivers, lakes, and oceans (Lipponen and Nikiforova, 2017). This, in addition to excess nutrients often present in agricultural runoff due to overuse and misuse of fertilizers, can lead to eutrophication, often causing irreparable damage to aquatic ecosystems. For these reasons, new techniques must be found to effectively recover waste nutrients and upcycle them into natural soil amendments that can be used to enrich soil quality and grow food for future generations while minimizing agricultural runoff. Duckweed is a small floating aquatic plant that can hyperaccumulate nutrients present in wastewater and agricultural runoff and then be harvested and reused to replace or supplement commercial soil fertilizers. As part of a two-year field trial, duckweed was tested for the second consecutive year in this study as a soil amendment in comparison to, and in combination with, commercial fertilizer for the growth of sorghum, a drought-resistant grain. Relative to fertilizer in all cases, soils amended with duckweed generated less ammonia and nitrate in surficial runoff. No differences in P in cumulative runoff were found among the different treatments (p = 0.509). Additionally, duckweed application produced sorghum grains with greater N and P content than other treatments (1.63 ± 0.03% N (p = 0.001) and 0.35 ± 0.0% P (p = 0.016)). Duckweed treatments also showed increased soil residue carbon and P after harvesting the crop. When normalized by germination rate, sorghum yield was similar across treatments. In agreement with first-year findings, the results indicated that duckweed may be a viable alternative to commercial fertilizer from an environmental and agricultural perspective, providing acceptable yields and contributing to the buildup of beneficial nutrients in the soil profile. Additional testing is needed to further evaluate potential germination inhibitors, greenhouse gas emissions (ex., N2O), and efficacy when applied to different crops and soil types.

Effect of bacterial biofertilizers, native arbuscular mycorrhizal fungi and soil amendments on soil and grain phosphorus availability of flooded rice in dry zone, Sri Lank

Rice is considered as the most important food crop in Sri Lanka and most of the Asian countries. Over the past three decades, rice farmers have become increasingly dependent on synthetic chemical phosphorous fertilizers, mainly triple super phosphate (TSP) as a source of phosphorous (P). However, dramatically increasing costs, serious environmental and health issues attached to chemical fertilizers, forced researchers to develop supplementary or alternate sources of P for rice. Hence, this study was done to evaluate the potential use of biofertilizers and natural soil amendments as alternatives to chemical P fertilizers in rice (Oryza sativa L.) farming in the dry zone of Sri Lanka. A field trial was carried out at Ranpathwela in Anuradhapura, North Central Province, Sri Lanka, during the Yala season in 2016. The experiment was designed as follows: CON: control; AMF: AMF inoculants (2 Mg ha-1); RAMF: ERP (153.3 kg ha-1) with the AMF inoculants (2 Mg ha-1); MC: mixed microbial culture (5 kg ha-1); RMC: ERP (153.3 kg ha-1) with a mixed microbial culture [consortium of Azospirillum sp., Pseudomonas sp. and Bacillus sp. (5 L ha-1)]; BC: biochar (6 Mg ha-1); CP: standard compost (10 Mg ha-1) and IF: inorganic synthetic fertilizer (125 N kg ha-1, 62.5 P2O5 kg ha-1 and 50 K2O kg ha-1). Three indigenous and two improved rice varieties were used. The experiment comprised of 24 plots and three replicates. Soil, roots and grains of rice were analyzed for phosphorus. Some other elements were shown to have an effect on plant available soil P such as aluminum and iron, were also estimated. It was revealed that significant differences (p<0.05) in variety, treatment and V x T interaction was observed in plant available soil phosphorus. The highest mean of available soil P was observed in TRSP2 x AMF (14.64 ± 0.12 mg kg-1) followed by TRSP3 x MC (8.87 ± 0.001 mg kg-1) interactions. The multifunctional microbial consortium in amended soil, including Azospirillum sp., Pseudomonas sp. Bacillus sp. and arbuscular mycorrhizal fungi, were capable of potentially increasing soil phosphorus. Furthermore, the addition of rock phosphate did not always make a difference in soil P availability for rice farming systems.

Changes in soil biochemical properties following application of bentonite as a soil amendment

Bentonite is a natural soil amendment that can reduce soil water loss and increase crop yield, but there are few studies about how bentonite influences soil biochemical properties. A field experiment was conducted with a millet [Setaria italic (L.) Beauv.] crop to evaluate the effect of bentonite amendments on soil biochemical properties including soil organic C, total N and total P, and soil microbial biomass C, N and P (MBC, MBN and MBP respectively) in the 0–20 cm soil layer in a semi-arid region in northern China from 2011 to 2015. Treatments included six rates of bentonite amendments (0, 6, 12, 18, 24 and 30 Mg ha−1) applied only in 2011, and a control with no bentonite amendment. Application of bentonite significantly increased soil microbial biomass parameters (MBC, MBN and MBP), soil organic C, and total N and total P over the five-year experimental period. MBC, MBN and MBP increases ranged from 5 to 50%, 3–42% and 3–34%, respectively; soil organic C, and total N and total P increases ranged from 1 to 15%, 1–19% and 0–17%, respectively. Bentonite also significantly increased MBC/MBN, MBC/MBP and MBN/MBP ratios, but it had no effect on soil C/N, C/P and N/P ratios. The application rate of 18 Mg ha−1 had the greatest effect in the first year, whereas 30 Mg ha−1 bentonite had the greatest effect in the fifth year. Increases in soil microbial activity and nutrient cycling and availability were attributed to higher soil water content accompanying the bentonite amendment resulting in improved plant growth and organic matter inputs to the soil providing increased substrates for microbes. Our results show that bentonite as a soil amendment can enhance sustainable agriculture production in semi-arid areas.

Use natural soil amendments in improving hydro-physical properties and wheat crop production of a new reclaimed area, Sohag governorate, Egypt

A field trial was carried out at The Experimental Farm of Al-Sheikh Allam Al-Monshaah, Sohag governorate, Egypt which is located at 26° 52- 41= N latitude and 31° 75- 96= E longitude during two successive growth seasons of 2017/18 and 2018/19 to investigate some natural soil amendments (poultry manure, PM; farmyard, FYM; compost, CO ; mud rock, MR) with two application levels (20 and 40 ton/ fed) (fed= feddan= 0.420 hectares = 1.037 acres) to assess their effects on soil hydro-physical properties and to find the suitable application level for wheat crop production. The results showed that the soil texture differed fromsand to loamy sand with slight no changes as a result of soil amendments applications (SA). The SA reduced the soil bulk density especially in the surface layer at high application level. They increased the saturation percentage, field capacity and available water. The positive effect of SA on the soil moisture constant could be arranged in the descending order of PM > CO > MR > FYM. The infiltration rate (IF) of surface layers differed from 0.17 to 0.68 cm/ hr. as an average of both growth seasons. The IF rate increased as the amount of SA increased. It is considered slow for FYM, CO and MR treatments and moderately slow for PM treatment. The effect of SA on IF could be sorted in the descending order of PM > FYM > CO > MR. The main hydraulic conductivity (HC) of both seasons of the top soil (50 cm) varies from 0.05 to 0.17 m/ day. It increased as the level of SA increased. It is also considered slow for FYM, CO and MR treatments and moderately slow for PM treatment. The effect of SA on the HC could be set in the descending order of PM > FYM > CO > MR.

Effect of Coal Gasification Fine Slag on the Physicochemical Properties of Soil

Coal gasification fine slag (CGFS), which is the by-product of entrained-flow coal gasification, has superior properties, such as a large surface area, a broad pore size distribution, and a high content of carbon. This material has the potential to amend poor soils. This study was carried out to investigate the use of CGFS as a soil amendment for alkaline sandy lands. Special focus was given to the mechanisms by which CGFS changes the physicochemical properties of soil. Characterization tests and chemical composition results further attested that the large amounts of residual carbon, fluffy structure, high surface area, and wide pore diameter of CGFS are key factors that enhance the soil physicochemical properties. When 20% CGFS was applied, the bulk density of the soil decreased from 1.47 to 1.05 g/cm3, the carbon content increased significantly from 4.86 to 55.38 g/kg, the pH decreased from 8.49 to 8.23, the cation exchange capacity (CEC) increased from 2.17 to 4.68 cmol/kg, and the water holding capacity (WHC) increased from 29 to 44%. Potted plant experiments in a greenhouse showed that 20%wt. incorporation of CGFS significantly increased the germination rates of maize and wheat from 0 to 100%. Pearson correlation analysis results indicated that the changes in the soil physicochemical properties were significantly correlated with each other (p < 0.05 or 0.01) and that the WHC was significantly correlated with the germination rates of the crops. This work demonstrated that judicious application of CGFS as a natural soil amendment could not only enhance the soil physicochemical properties but also provide a new approach for the safe and environmentally friendly utilization of CGFS.

The Role of Soil Amendment on Tropical Post Tin Mining Area in Bangka Island Indonesia for Dignified and Sustainable Environment and Life

Openly tropical tin mining in Bangka Island Indonesia expose heavy metal that had been buried became a part of our environment and life. This has become a major cause of land degradation and severe local-global environmental damages. This study aims to accelerate reconsolidation of degraded ecosystems on the former tin mine land, to increase land productivity and dignified environment through appropriate rehabilitation technology on marginal land that is inexpensive, environmentally friendly and sustainable. This study is a part of a roadmap research activities on the rehabilitation of degraded land in tropical ecosystem, that consist of (a) characterization of degraded tin mining lands through the determination of chemistry, physics, biology and mineral soil properties, (b) introducing multi-function pioneers plant for acceleration of peak pioneer plant in the reestablishment of degraded tin mining ecosystem (c) management of natural soil amendment (volcanic ash, organic waste materials and legume cover crop as a material for soil amelioration to increase land productivity, (d) role of biotechnology through the application of local bio-fertilizer (mycorrhizae, phosphate soluble bacteria, rhizobium). Soil from post tropical tin mining acid soil (pH 4.97) that dominated by sand particles (88%) with very low cation exchange capacity, very low nutrient contents (available and total-N, P, K, Ca, Mg) and high toxicity of Zn, Cu, B, Cd and Ti, but still have low toxicity of Al, Fe, Mn, Mo, Pb, As. Soil amendment of biogas and volcanic ash could improve soil quality by increasing of better pH, high available-P and cation exchange capacity and maintained their low toxicity. The growth (high, diameter, biomass, top-root ratio) of exotic pioneer plant of Kemiri sunan (Reutealis trisperma) increased in the better soil quality that caused by application of proper soil amendment. The grand concept and appropriate technology for rehabilitation of degraded tin-mining land ecosystems in tropical regions which are the lungs of the world have a high contribution for development of our dignified and sustainable environment and life.

Effect of phosphorus and potassium fertilization on growth and yield of corn plants under different natural soil amendments

Effect of phosphorus and potassium fertilization on growth and yield of corn plants under different natural soil amendments

ENHANCING COPPER AND LEAD BIOACCUMULATION IN RAPESEED BY ADDING HEMP SHIVES AS SOIL NATURAL AMENDMENTS

The current study reveals the results of a phytoremediation process applied to a multi metal contaminated soil, located in close proximity to an energy power plant. Phytoremediation process was studied using the rapeseed cultivation, both in the presence and absence of hemp shives, considered as potential natural soil amendments. The physiological responses of the rapeseed plants, such as variations in length and accumulation of biomass, as well as the content of assimilating pigments were investigated. The concentrations of Cu (II) and Pb (II) ions have also been determined in soil and plants aiming at locating the metal ions in different organs of the plants. By using hemp shives as amendments, bioaccumulation of copper and lead ions in plant increases. The plants cultivated in the presence of high amounts of heavy metal ions have been characterized by an inhibition of growth and development that consisted in decrease of root and stem lengths, as well in the amount of biomass accumulated in different vegetative organs.