Zeolite and Vermiculite as Inorganic Soil Amendments Modify Shoot-Root Allocation, Mineral Nutrition, Photosystem II Activity and Gas Exchange Parameters of Chestnut (Castanea sativa Mill) Plants

Theocharis Chatzistathis,Evgenia Papaioannou,Ioannis E Papadakis,Anastasia Giannakoula

doi:10.3390/agronomy11010109

Abstract

One of the most challenging topics for the sustainable agriculture is how to decrease high fertilization rates. A pot experiment, exploring the effects of zeolite (ZEO) and/or vermiculite (VER) as soil amendments, comparing to the soil application of a controlled release fertilizer (CRF), was realized in chestnut plants. Various parameters related to soil fertility, and plant growth, nutrition, and physiology were investigated to gain knowledge towards more sustainable management. After ZEO application and in comparison to CRF, an impressive boost in soil K was achieved. Moreover, soil P and Zn levels were higher in the VER-treated soil, compared to CRF. Leaf K and Ca concentrations were significantly higher in ZEO, compared to the VER treatment; the highest foliar N and Zn concentrations were measured in CRF and VER, respectively. However, significantly lower foliar Mn and Cu were found in VER. The highest root biomass produced in the ZEO treated plants. For most nutrients, their total uptake per plant was higher in CRF and ZEO. Finally, photosynthetic rates were higher in VER (mainly due to non-stomatal factors) and CRF (mainly due to stomatal factors). Our data open a discussion towards the application of ZEO and/or VER as soil amendments in chestnut nurseries and orchards, aiming at partially decreasing fertilization rates and boosting sustainable nutrient management.

Highlights

Chestnut (Castanea sativa Mill) has been used for centuries, for both wood and fruit production
Our study proves that water use efficiency (WUEi) was influenced by organic soil amendments, and by the application of inorganic soil amendments, such as ZEO and VER
ZEO addition leaded to an impressive boosting in exchangeable K concentration of more than 30 times, compared to the control soil (CRF treatment)

Summary

Introduction

Chestnut (Castanea sativa Mill) has been used for centuries, for both wood and fruit (nut) production. Wood production is declining due to the fall in price, the production of nuts is expanding in mountainous areas [1]. During the last years, chestnut management cultivation has been shifted from abandoned, huge, isolated trees of low density to more intensified cropping systems of higher plant density; this practice includes chemical fertilization, pruning and mechanical harvesting. This shift in chestnut management cultivation may be explained by the higher profit that recently nut prices may provide to the growers [1]. Most of the existing published papers on C. sativa Mill are mainly focused on the improvement of its germination and micro-propagation [4,5,6], as well as on the non-destructive leaf area estimation [7]

Methods

Results

Discussion

Conclusion