The aim of this study was to provide an overview of the approaches and methods used to assess the dynamics of soil organic matter (SOM). This included identifying relevant processes that describe and estimate SOM decomposition, lability, and humification for the purpose of sustainable management. Various existing techniques and models for the qualitative and quantitative assessment of SOM were evaluated to gain a better understanding of advances in organic matter transformation. This evaluation aimed to identify the strengths, limitations, and applications of these techniques and models, and to highlight new research directions in the field. Quantitative analysis of SOM can be performed using various parameters, including oxidation kinetics, lability, carbon management index, humification degree, humification index, and humification ratio. On the other hand, qualitative evaluation of SOM can involve techniques such as oxidizability, high-performance size-exclusion chromatography, electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry, visual examination, smell, assessment of microorganism content, plant growth, cation exchange capacity, type of organic material, and decomposition. These techniques and parameters provide valuable insights into the characteristics and transformation of SOM, enabling a comprehensive understanding of its dynamics. Evaluating SOM dynamics is of utmost importance as it is a determining factor for soil health, fertility, organic matter stability, and sustainability. Therefore, developing SOM models and other assessment techniques based on soil properties, environmental factors, and management practices can serve as a tool for sustainable management. Long-term or extensive short-term experimental data should be used for modeling to obtain reliable results, especially for quantitative SOM transformation analysis, and changes in the quality and quantity of SOM should be considered when developing sustainable soil management strategies.

Global deposits of concentrated phosphates, which are a necessary source for the production of phosphate fertilizers, are limited. These reserves keep getting thinner, and every day, large amounts of phosphorus end up in watercourses. In this study, we verified that modified biochar (saturated with FeCl₃ solution and then neutralized with NaOH solution) can adsorb significant amounts of phosphorus from wastewater. Moreover, the agrochemical qualities of sludge water from a municipal wastewater treatment plant, struvite, phosphorus-saturated biochar, and iron(III) phosphate from a reused biochar filter were tested in this study. We determined the amount of mobile phosphorus as well as the amount of extractable phosphorus and its five fractions. It was found that modified biochar can hold one-third of the phosphorus amount contained in the commonly used agricultural fertilizer simple superphosphate (1 × 10⁵ g of modified biochar captures up to 2.79 × 10³ g of P). Moreover, plants can more easily access phosphorus biochar fractions than struvite, which is formed spontaneously during sludge management. The results of this research prove that the proposed method of recycling phosphorus from wastewater can be applied in technological practice.

Wheat (Triticum aestivum L.) is a strategic agricultural crop that plays a significant role in maintaining national food security and sustainable economic development. Increasing technical performance considering lowering costs, energy, and environmental consequences are significant aims for wheat cultivation. For drylands, which cover approximately 41% of the world’s land surface, water stress has a considerable negative impact on crop output. The current study aimed to assess the environmental aspects of chemical fertilizer in combination with compost in dryland and irrigated winter wheat production systems through life cycle assessment (LCA). The cradle-to-farm gate was considered as the system boundary based on one tone of wheat yield and four strategies: D-C (dryland with compost), D (dryland without compost), I-C (irrigated with compost), and I (irrigated without compost). Based on the results, the highest and lowest amounts of wheat yield were related to the I-C and D strategies with 12.2 and 6.7 ton ha⁻¹, respectively. The LCA result showed that the I strategy in comparison with other strategies had the highest negative impact on human health (49%), resources (59%), ecosystem quality (44%), and climate change (43%). However, the D-C strategy resulted in the lowest adverse effect of 6% on human health, 1% on resources, 10% on ecosystem quality, and 11% on climate change. Utilizing a combination of fertilizer and compost in dryland areas could ensure a higher yield of crops in addition to alleviating negative environmental indicators.