"Sol" C#11

Noticable stalling of vertical growth around 5-600ppfd at 18 hours, apicial dominance not broken but side stems shooting up to around same ppfd range then slows to stay just under apex. Amended soil with biochar charged to ratio of 88:11:1 Ca:Mg:K. It is commonly said that an ideal soil is 50% pore space (water + air), 5 % organic matter, and 45% minerals. The ideal mixture for plant growth is called a loam and has roughly 40% sand, 40% silt and 20% clay. Cation exchange capacity (CEC) is a measure of how many positively charged ions, or cations, a soil can hold and exchange. CEC is a reflection of a soil's fertility and ability to supply nutrients to plants. More bruh science for pretend gurus. Negative charges Soil particles have negative charges, which attract positively charged cations. Exchange Cations are not tightly held to the soil particles, so they can be exchanged with other cations in the soil water. Plant uptake Plant roots remove cations from the soil solution, which are then replaced by cations from the soil particles. Factors that affect CEC Clay and organic matter Clay and organic matter particles in soil have negative charges, which attract and hold cations. Organic matter has more exchange sites than clay. pH As soil pH increases, the number of negatively charged sites on colloids increases, which allows the soil to hold more cations. How CEC is measured  CEC is measured in millequivalents per 100 grams of soil ((meq/100g)). A meq is the number of ions that total a specific quantity of electrical charges. CEC is important for understanding how to irrigate different soils. Soils with low CEC need frequent, short irrigation, while soils with high CEC need less frequent, longer irrigation. Organic matter has a very high CEC ranging from 250 to 400 meq/100 g (Moore 1998). Because a higher CEC usually indicates more clay and organic matter is present in the soil, high CEC soils generally have greater water holding capacity than low CEC soils. https://www.extension.purdue.edu/extmedia/ay/ay-238.html Percent base saturation (BS) is the percentage of the CEC occupied by the basic cations Ca2+, Mg2+ and K+. Basic cations are distinguished from the acid cations H+ and Al3+. At an approximate soil pH 5.4 or less, Al3+ is present in a significantly high concentration that hinders growth of most plant species, and the lower the soil pH, the greater the amount of toxic Al3+. Therefore, soils with a high percent base saturation are generally more fertile because: 1 They have little or no acid cation Al3+ that is toxic to plant growth. 2 Soils with high percent base saturation have a higher pH; therefore, they are more buffered against acid cations from plant roots and soil processes that acidify the soil (nitrification, acid rain, etc.). 3 They contain greater amounts of the essential plant nutrient cations K+, Ca2+ and Mg2+ for use by plants. The percentage base saturation is expressed as follows: %BS = [(Ca2+ + Mg2+ + K+)/CEC] × 100 Depending on soil pH, the soil's base saturation may be a fraction of CEC or approximately equal to CEC. In general, if the soil pH is below 7, the base saturation is less than CEC. At pH 7 or higher, soil clay mineral and organic matter surfaces are occupied by basic cations, and thus, base saturation is equal to CEC. Figure 2 illustrates the relative amount of cations retained on soil surfaces at various soil pH levels. A soil's CEC affects fertilization and liming practices. For example, soils with high CEC retain more nutrients than low-CEC soils. With large quantities of fertilizers applied in a single application to sandy soils with low CEC, loss of nutrients is more likely to occur via leaching. In contrast, these nutrients are much less susceptible to losses in clay soils. Crop production releases acidity into soil. Soil pH will decrease more due to crop production on low CEC soils. High CEC soils are generally well buffered such that pH changes much less from crop production. Therefore, sandy soils low in CEC need to be limed more frequently but at lower rates of application than clay soils. Higher lime rates are needed to reach an optimum pH on high CEC soils due to their greater abundance of acidic cations at a given pH. The average CEC of coco coir is between 40-100 (meq/100g)  Organic matter has a very high CEC ranging from 250 to 400 meq/100 g Cation exchange capacity (CEC) is a critical soil property that directly influences nutrient availability and plant growth. The determination of CEC can be achieved through direct measurement or by summation methods, with the latter encompassing techniques such as the Mehlich-3 (M3) and ammonium acetate (AA) extractions (1). Direct measurement of CEC involves the displacement of exchangeable cations on soil particles with a solution containing a known concentration of an index cation, typically ammonium (NH4+), and subsequent quantification of the NH4+ adsorbed. This method offers precise results but requires specialized laboratory equipment and is time-consuming (2). In contrast, summation methods involve the extraction of cations from soils with specific reagents, with the extracted cations subsequently quantified. The M3 extraction uses a mixture of ammonium fluoride (NH4F) and nitric acid (HNO3) to release exchangeable cations, while AA is utilized to displace cations (3). Summation methods are quicker and more convenient for routine soil analysis but may overestimate CEC as they also extract non-exchangeable cations from the soil (3). Therefore, the choice between direct measurement and summation methods for CEC determination depends on the research objectives and available resources. Direct measurement is preferable when high accuracy is required, whereas summation methods like M3 and ammonium acetate extractions are suitable for rapid assessment of CEC in routine soil analyses. Moreover, determining CEC is valuable for understanding the relationship between key cations (K, Ca, and Mg) in soil and their impact on plant uptake and development. Overall, using practical soil nutrient extraction and summation methods for CEC determination offers benefits such as cost-efficiency, accessibility, speed, ease of implementation, versatility, and the ability to assess predictive accuracy compared to more complex techniques like the direct measurement method (4). Furthermore, CEC via summation represents the soil’s capacity to hold and exchange cations and helps assess nutrient availability, cation competition, and potential imbalances in these essential nutrients. Notwithstanding, the assumption that increasing soil CEC is always beneficial requires nuanced consideration. Particularly in the context of tropical soils, where H+Al (hydrogen and aluminum) constitutes a significant portion of the soil CEC, a sole focus on increasing CEC might not be advantageous if the nutrient balance is skewed towards detrimental elements like Al (5–7). Moreover, a global perspective underscores the fact that excessively high CEC does not necessarily guarantee optimal soil fertility (8). High CEC soils may indicate a propensity for nutrient imbalances, where certain nutrients may be overly abundant or deficient. For instance, soils with high CEC might accumulate an excess of cations such as sodium (Na), particularly in regions already high in Na or where excessive Na addition occurs (9). This surplus could potentially lead to soil sodicity and create unfavorable physical conditions for plant growth. Calcium, Mg, and K are essential cations that interact on soil exchange sites, influencing soil structure, fertility, and plant nutrition. The soil CEC, determined by clay and organic matter composition, serves as the battleground for these competitive interactions. Calcium, due to its smaller hydrated radius relative to Mg, tends to dominate exchange sites, forming robust bonds with negatively charged sites on clay and organic matter (10). This dominance influences soil structure and can limit the availability of other cations. Magnesium, an essential nutrient for plants, competes with Ca for exchange sites, resulting in calcium-magnesium interaction (11). Potassium, another critical plant nutrient, also competes for exchange sites with Ca and Mg (12), with Ca and Mg being preferentially adsorbed (13, 14). The intricate interplay of these cations on exchange sites has implications for nutrient uptake by plants, potentially leading to imbalances and affecting overall soil fertility. Imbalances in cation ratios may result in nutrient deficiencies, emphasizing the importance of understanding these competitive interactions for sustainable soil management and agricultural practices. In addition to the intricate cation interactions, the incorporation of biochar into soils has emerged as a noteworthy factor influencing soil CEC. The porous structure and high surface area of biochar provide abundant binding sites for cations (15), contributing to increased CEC. This augmentation in CEC not only affects the retention and availability of essential nutrients but also influences the competitive dynamics among cations. Furthermore, the introduction of biochar can alter the soil’s physicochemical properties, influencing its overall fertility and promoting sustainable agricultural practices (16). As a result, understanding the interplay between traditional cations, such as Ca, Mg, and K, and the transformative impact of biochar on CEC is crucial for developing holistic strategies to optimize soil health and fertility. This study aimed to investigate the influence of biochar on soil CEC. Our specific objectives were: 1. Investigate the influence of switchgrass-derived biochar (SGB) and poultry litter-derived biochar (PLB) on soil CEC through experiments without and with ryegrass cultivation, assessing five biochar application rates. 2. Evaluate the role of soil extractable calcium and magnesium/potassium ratio ([Ca+Mg]/K) concerning soil CEC for plant growth, aiming to establish optimal ryegrass production thresholds. 3. Develop predictive models for post-biochar application on soil CEC changes. This comprehensive verification process ensures at which level biochar effectively enhances soil nutrient availability (while simultaneously binding and immobilizing contaminants as demonstrated in a previous study by 17). We hypothesized that (i) biochar application will alter soil CEC, (ii) the properties of the biochar, such as ash content, will play a critical role in influencing soil CEC dynamics, (iii) the calcium and magnesium/potassium ratio ([Ca+Mg]/K) will be of greater importance than CEC alone for ryegrass growth in biochar-amended soils, and (iv) predictive models for soil CEC changes post-biochar application can be developed relying on initial soil and biochar CEC. https://www.frontiersin.org/journals/soil-science/articles/10.3389/fsoil.2024.1371777/full Aluminium(3+) is an aluminium cation that has a charge of +3. It is an aluminium cation, a monoatomic trication and a monoatomic aluminium. When considering the cation exchange capacity (CEC) of biochar and the ratio of calcium (Ca), magnesium (Mg), and potassium (K), a typical ideal ratio is often cited as Ca:Mg:K = 88:11:1; meaning that for optimal plant growth, the majority of the exchangeable cations on the biochar should be calcium, with smaller proportions of magnesium and potassium respectively. Key points about CEC and biochar Ca:Mg:K ratio: This ratio is significant because it affects nutrient availability for plants, with calcium playing a crucial role in cell wall structure and magnesium being important for chlorophyll synthesis, while potassium is involved in enzyme activation. Impact of biochar type: The exact optimal ratio can vary depending on the type of feedstock used to produce the biochar, as different biomass sources will have varying mineral compositions. Soil analysis is key: To determine the best Ca:Mg:K ratio for your specific soil, it's important to conduct a soil test to analyze the existing cation balance. https://www.sciencedirect.com/science/article/pii/S0959652624009028