Biogas Generation from Maize and Cocksfoot Growing in Degraded Soil Enriched with New Zeolite Substrate

Degraded lands are potential areas for obtaining biomass which can serve as an energy source after its conversion into biogas. Thus, the studies on biogas production from maize and cocksfoot biomasses obtained from degraded soil supplemented with additions of new zeolite substrate (Z-ion as the nutrient carrier) and on arable soil (reference soil) were carried out during batch digestion tests. It was found that the biogas and biomethane potentials and specific energy of the test species growing in degraded soil enriched with Z-ion additions (1% and 5% v/v in the cases of cocksfoot and maize, respectively) did not differ significantly from the values of these parameters that were found for the plants growing in arable soil. The application of Z-ion to the degraded soil (especially in a dose of 5% v/v) resulted in an increase in the nitrogen content and decrease (below the lower optimum value) in the C/N ratio in the plant biomass. However, these changes did not negatively influence the final values of the biogas or methane potentials or the specific energy found for the maize biomass. Therefore, the study results indicated the usefulness of Z-ion substrate for improving the growth conditions for energy crops in degraded soils and, as a consequence, obtaining a plant feedstock suitable for the digestion process.

The Valorization of Biolignin from Esparto Grass (Stipa tenacissima L.) Produced by Green Process CIMV (Compagnie Industrielle de la Matière Végétale) for Fertilization of Algerian Degraded Soil: Impact on the Physicochemical and Biological Properties

This study proposes a new use for a paper industry waste material, lignin, in agriculture and agronomy as a fertilizer for arid soils, while following a strategy aiming to both increase the amount of organic matter in these soils and decrease the impact of pollution caused by industrial discharges that contain organic and/or inorganic pollutants generated by the paper industry. In fact, this method works to improve soil quality through a new carbon-rich bioorganic fertilizer (biolignin) that results from a green method called CIMV, a targeted depollution objective of the paper industry. Over the course of 180 days, we monitored the physicochemical and biological characteristics of degraded soils treated with three different biolignin treatments of 0 (D0), 2 (D1), and 4 (D2) g/kg. The humification was then evaluated by the equation E4/E6. A remarkable variation of the physicochemical and biological parameters was observed in D1 and D2: temperature 12–38 °C, humidity 9–29%, and pH 7.06–8.73. The C/N ratio decreased from 266 to 49. After 180 days, the improvement in soil carbon content for the three treatments D0, D1, and D2 was 14%, 19%, and 24%, respectively. A maximum bacterial biomass of 152 (CFU/g soil) was observed on the 30th day for D1. Maximum laccase activity for D2 was observed on the 120th day. D1 and D2 recorded a significant degree of humification compared to D0. The best indicator of humification E4/E6 was observed in D1, where the value reached 2.66 at the end of the treatment period. The D2 treatment showed a remarkable effect improving the fertility of the degraded soil, which confirms that biolignin is a good fertilizer.

Reaction of Microorganisms to Long-Term Waste Reclamation of Soil Degraded by the Sulfur Mining Industry

The research was carried out to assess soil condition many years after waste introduction for reclamation purposes. The parameters of the activity of soil microorganisms responsible for the revitalization processes in degraded soils were used in the research. Soil material was derived from the area of the former sulfur mine. The results showed that even a single waste introduction to degraded soil caused long-lasting effects in the activity of soil microorganisms. The most favorable changes were caused by the addition of sewage sludge and the use of mineral wool in the form of a pad. The application of lime alone turned out to be the least beneficial for the revitalization processes, i.e., restoring the homeostasis of biological life in degraded soil. This research is a continuation of study that concerned the initial recultivation period. The obtained research results show the need for monitoring soils reclaimed with waste, not only in the initial period but also in the following years. These results allow evaluation of the usefulness of the parameters of soil microbial activity in monitoring soil environments subjected to strong human pressure. The results can be used to assess the risks associated with the introduction of waste into the environment.

Agricultural Production on Erosion-Affected Land from the Perspective of Remote Sensing

In this article, we discuss the influence of soil erosion on crop yield in the erosion-prone chernozem region of South Moravia. Erosional and depositional areas show significant differences in soil properties, which are also reflected in total crop yield. Plots of winter wheat, grown during the years 2016–2019 were used for analysis. The Enhanced Vegetation Index (EVI), referred to in literature as one of the best correlates of yield, was used to provide indirect information on yield. Although erosional areas are visible on orthophoto images on chernozem soils, the necessary orthophoto images are not always available. Thus, we have proposed a method for the identification of such erosion-affected areas based on the use of Sentinel 2 satellite images and NDVI or NBR2 indices. The relationship between yield and erosion was expressed through Pearson’s correlation on a sample of pixels randomly selected on the studied plots. The results showed a statistically significant linear reduction in yield depending on the level of degradation. All plots were further reclassified, according to level of degradation, as high, medium, or low state of degradation, where the average EVI values were subsequently calculated. Yield on non-degraded soil is 16 ± 1% higher on average.

Soil structure: its importance to resilient pastures in New Zealand (review)

Soil structure is critical to soil quality due to its influence on many soil processes and functions, including water storage and transport, the oxygen supply, the emission of greenhouse gases, and biological processes such as carbon and nitrogen mineralisation, nitrification and denitrification. These soil functions underpin key ecosystem services such as pasture production, nutrient cycling and mitigation of contaminant losses to receiving waters. The paper discusses key soil physical indicators relevant to pasture performance and the environment, including soil porosity, bulk density and hydraulic conductivity. In regions with robust programs for monitoring soil quality, e.g., Waikato, Canterbury, Auckland, Marlborough and Wellington, soil compaction is found to be widespread under pastoral land-use. The specific consequences of degraded soil quality on pasture production and financial implications remain unclear, at farm, regional and national levels. The range of impacts of soil structural damage on pasture yield, persistence, farm system response, and management practices that minimise or repair damage are presented. Knowledge gaps and further research needs are also summarised.

Soil fertilization synergistically enhances the impact of pollination services in increasing seed yield of sunflower under dryland conditions

To exploit the potential of ecological intensification during sunflower cropping, it is crucial to understand the potential synergies between crop management and ecosystem services. We therefore examined the effect of pollination intensification on sunflower yield and productivity under various levels of soil fertilization over two seasons in the eastern Free State, South Africa. We manipulated soil fertility with fertilizer applications and pollination with exclusion bags. We found a synergetic effect between pollination and soil fertilization whereby increasing pollination intensity led to a far higher impact on sunflower yield when the soil had been fertilized. Specifically, the intensification of insect pollination increased seed yield by approximately 0.4 ton/ha on nutrient poor soil and by approximately 1.7 ton/ha on moderately fertilized soil. Our findings suggest that sunflower crops on adequate balanced soil fertility will receive abundant insect pollination and may gain more from both synergies than crops grown in areas with degraded soil fertility.

Feasibility Study on the Application of Microbial Agent Modified Water-Jet Loom Sludge for the Restoration of Degraded Soil in Mining Areas

Open-pit mining causes soil damage and affects the health of the ecosystem. In the arid grassland mining areas, the soil is severely sanded, water-starved, and saline, thus making it difficult for plants and microorganisms to survive. Water-jet loom sludge can be used to improve the quality as it contains a lot of clay and is rich in organic matter, which provides a material basis for microorganism activity. To explore the effects of microbial agent-modified water-jet loom sludge on the restoration of degraded soil in grassland mining areas, four pot trials were set up, i.e., for untreated soil, the application of a microbial agent alone, the application of water-jet loom sludge alone, and the combined application of water-jet loom sludge and the microbial agent. The results show that (1) microbial agent-modified sludge can improve soil water-holding capacity and aggregate stability; (2) the nutrient content of the restored soil fraction increased significantly, and the pH of the original saline soil decreased from 9.06 to 7.84; (3) this method significantly increased plant biomass and microbial biomass carbon and enhanced the abundance and diversity of fungi and bacteria. The three treatments had different results in different soil properties, and the effect of the combined water-jet loom sludge and microbial agent treatment on soil remediation was significantly better than the individual application of either.

Influence of INGER and TORDIS Energetic Willow Clones Planted on Contaminated Soil on the Survival Rates, Yields and Calorific Value

The paper presents some forestry aspects of using Inger and Tordis willow clones to obtain woody biomass and remedy degraded soils. The methodological aspects regarding the planting of willow seedlings, the evaluation of the survival rate, the evaluation of the biomass quantity and the enrichment of the soil are analyzed. The results of the experiments showed that the degraded soil decreased the viability rate of the cuttings by 16.6% for the Tordis clone and 35.8 for the Inger clone. The analysis of the soil samples showed that it was enriched in nutrients after 2 years of cultivation, by the decomposition of the fallen leaves on the soil and by the absorption of the substances from the soil. Regarding the amount of biomass, its mass per hectare after the first year of cultivation was 0.64 t/ha for the Inger clone and 0.66 t/ha for the Tordis clone, while the calorific values of 19,376 kJ/kg for Inger and 19,355 kJ/kg for Tordis were good values. The final conclusion of the paper highlights that Osier willow is a viable solution for obtaining energetic biomass and putting it back into the productive circuit of degraded soils.