Effect of Low Zeolite Doses on Plants and Soil Physicochemical Properties

Abstract

Thousands of tons of zeolitic materials are used yearly as soil conditioners and components of slow-release fertilizers. A positive influence of application of zeolites on plant growth has been frequently observed. Because zeolites have extremely large cation exchange capacity, surface area, porosity and water holding capacity, a paradigm has aroused that increasing plant growth is caused by a long-lasting improvement of soil physicochemical properties by zeolites. In the first year of our field experiment performed on a poor soil with zeolite rates from 1 to 8 t/ha and N fertilization, an increase in spring wheat yield was observed. Any effect on soil cation exchange capacity (CEC), surface area (S), pH-dependent surface charge (Qv), mesoporosity, water holding capacity and plant available water (PAW) was noted. This positive effect of zeolite on plants could be due to extra nutrients supplied by the mineral (primarily potassium—1 ton of the studied zeolite contained around 15 kg of exchangeable potassium). In the second year of the experiment (NPK treatment on previously zeolitized soil), the zeolite presence did not impact plant yield. No long-term effect of the zeolite on plants was observed in the third year after soil zeolitization, when, as in the first year, only N fertilization was applied. That there were no significant changes in the above-mentioned physicochemical properties of the field soil after the addition of zeolite was most likely due to high dilution of the mineral in the soil (8 t/ha zeolite is only ~0.35% of the soil mass in the root zone). To determine how much zeolite is needed to improve soil physicochemical properties, much higher zeolite rates than those applied in the field were studied in the laboratory. The latter studies showed that CEC and S increased proportionally to the zeolite percentage in the soil. The Qv of the zeolite was lower than that of the soil, so a decrease in soil variable charge was observed due to zeolite addition. Surprisingly, a slight increase in PAW, even at the largest zeolite dose (from 9.5% for the control soil to 13% for a mixture of 40 g zeolite and 100 g soil), was observed. It resulted from small alterations of the soil macrostructure: although the input of small zeolite pores was seen in pore size distributions, the larger pores responsible for the storage of PAW were almost not affected by the zeolite addition.

Growth analysis of sweet corn plants treated with a soil amendment

“…The Net Assimilation Rate (NAR) of the plant at 15 days after planting positively correlated with the NAR of the plant at 45 days after planting (0.640) and the plant at 75 days after planting (0.749), as well as negatively correlated with the yield (Y) (-0.859). Similarly, the NAR of the plant at 45 days after The increase in production as a result of the addition of Zeolite may result from the release of potassium, calcium, magnesium and some microelements to the root zone by the zeolite exchange complex [11]. Since all plots of land were fertilized with the same amount of nitrogen, there should be no difference in yield; however, the combined effect of zeolite and nitrogen gives important results in this regard, as stated by [12], who observed that the use of zeolites increased the effectiveness of nitrogen application in the soil by about 16-22% due to better nitrogen distribution in the soil.…”

Effects of biochar, zeolite and mycorrhiza inoculation on soil properties, heavy metal availability and cowpea growth in a multi-contaminated soil

“…Zhuo et al 30 found that soil treated with a combination of biochar and mycorrhiza had a considerable increase in pH. Moreover, various researchers reported that biochar and zeolite increase the soil EC value 54 .…”

Fertilizer technology based on optimized nitrogen release from urea‐loaded natural superabsorbent carriers

“…In the last decade, research on natural super absorbents (NHAs) as environmental friendly and cost-effective alternatives to synthetic SAPs has greatly accelerated. Because of the very low swelling capacity of inorganic natural superabsorbent (Chen et al, 2021;Ibrahim & Alghamdi, 2021;Noh et al, 2015;Omar et al, 2015Omar et al, , 2017 and their adverse effects on the soil fertility and structure (Liu et al, 2017;Szatanic-Kloc et al, 2021), focus has been placed on the NHAs based on large volume biopolymers from either the group of polysaccharides or proteins (Abdulhameed et al, 2020;Llanes et al, 2020;Muhammad et al, 2016;Sarmah & Karak, 2020;Xi & Zhang, 2021;Xiao et al, 2017;Zou et al, 2012). Cellulose, starch, chitosan, various gums and gelatin are the most frequently considered naturally sourced components for NHAs.…”