Ammonium fixation and release by clay minerals as influenced by potassium

Abstract

It is postulated that stabilized ammonium fertilizers improve fertilizer-N utilization by crops, leading thus to higher yields with the same fertilizer rate, especially on sandy soils. However, it must be taken into consideration that in clayey soil at least a part of the NH 4 + ions may be fixed by 2:1 clay minerals, thus delaying the effect of the N fertilizer. Because NH 4 + and K + have similar size and valence properties and therefore compete for the same non-exchangeable sites of 2:1 clay minerals, we investigated the influence of time and K + application rate on both fixation and release of NH 4 + . Fixation of NH 4 + ions was higher when K + was applied after NH 4 + , while the influence of the K + application rate was less pronounced. Mobilization of non-exchangeable NH 4 + was retarded when K + was applied at the high rate after NH 4 + . At the first harvest yield formation of ryegrass was neither influenced by the amount as well as the application time of K + , because plant available N was not growth limiting, while yield of the second harvest was significantly higher with the low K + application rate after NH 4 + . After the second harvest the blocking effect of K + on the release of non-exchangeable NH 4 + was attenuated and the highest yields of the third cut were reached in the treatments with the high K + application rate after NH 4 + . Total dry matter yield was highest when K + was applied at the low rate after NH 4 + . Our results show that K + governs fixation and release of non-exchangeable NH 4 + , which should be taken into consideration when applying ammonium containing N fertilizers like ammonium sulfate, ammonium sulfate nitrate and ENTEC. Thus K + can affect N availability when N is applied as NH 4 + in both the short and long term.

Influence of Clay Minerals on Some Soil Fertility Attributes: A Review

“…Clay mineralogy appears to be one of the most important indicators of soil quality [12], and proper knowledge of the clay mineralogy of a soil has significant practical implications on the use of fertilizers, on application and management [13] [14] [15] [16], and on the bioavailability of heavy metals in soil [17]. Furthermore, soil mineralogy-soil fertility relationship is a basic component in understanding and interpreting the results of fertility experiments and soil analytical data, especially in developing fertilizer recommendation systems [18] [19] [20].…”

Response of corn yield to water retaining agents, inhibitors, and corn stalks addition in semi-arid cropland,

“…These can allow some small molecules or ions to diffuse into the water retaining agents' molecules and be wrapped by the agents in their water-swollen condition. Alternatively, the nutrients can be temporarily fixed by cation exchange and adsorption within the agents (Li et al 2014), resulting in the reduction of available P. The effect of PAM on exchangeable K and K-PAA on NH4 + -N may be caused by the competition between NH4 + -N and potassium ions on the 2:1 clay mineral interlayers (Scherer et al 2014). Addition of inhibitors decreased the contents of NH4 + -N (29.1%, Table 2 and Table S2) and available P (16.0%, Table 4 and Table S4) in the corn seedling stage, NO3 --N (21.63%, Table 3 and Table S3) and available P (27.2%, Table 4 and Table S4) in the jointing stage, and NH4 + -N (18.3%, Table 2 and Table S2) in the mature stage.…”

“…However, excessive fertilization in production practices can lead to a serious imbalance between the available nutrients provided by soil and the actual needs of crops (Cui et al 2022). To deal with this problem, urea inhibitors and nitrification inhibitors are added to fertilizers to regulate the transformation process of fertilizer N in soil (Scherer et al 2014;. Urease inhibitors can delay urea hydrolysis by inhibiting urease activity.…”

Application of litters to inhibit nitrification in Vertisols on sweet corn (Zea mays S.)

“…Vertisols have relatively rich nutrient reserves, although they are not yet available for plants (Dudek et al, 2019). Soil Vertisols have a high negative charge, so ammonium is more absorbed by soil particles, whereas nitrate moves freely in the soil and diffuses into the plant tissue (Scherer et al, 2014). Ammonium content in Vertisols' stagnant soil water is lower than the nitrate because Vertisols has variable minerals that can adsorb ammonium and nitrate.…”