Chemical Properties and Enzyme Activity of Soil as Affected by Tillage System and Previous Crop

Woźniak Woźniak

doi:10.3390/agriculture9120262

Abstract

The objective of this study was to evaluate the effect of tillage system and previously cultivated crop on the chemical properties and enzyme activity of soil. The first-order experimental factor was the tillage system, i.e., (1) conventional tillage (CT) and (2) reduced tillage (RT), whereas the second-order experimental factor was the previously cultivated crop, i.e., a) pea and b) durum wheat. Samples of soil were analyzed for the contents of organic C, total N, available forms of P, K, and Mg, as well as soil pH, total sorption capacity, and activity of soil enzymes (dehydrogenases, phosphatases, ureases, and proteases). The study demonstrated that the contents of organic C, total N, and available forms of K and Mg as well as soil pH were higher in soil subjected to RT than in that subjected to CT. In plots after pea cultivation, higher values were determined for the contents of total N and Mg, whereas in plots after durum wheat cultivation, the contents of organic C, P, and K and the soil pH were higher. Higher activities of dehydrogenases and phosphatases in soil were noted in soils subjected to the CT system than in those subjected to the RT system, whereas the activities of ureases and proteases were higher in soils subjected to RT. In addition, higher activities of dehydrogenases, phosphatases, and proteases were determined in the soil after pea cultivation than after durum wheat cultivation, whereas a higher activity of ureases was found in the soil after durum wheat cultivation. The C/N ratio was more beneficial after CT than after RT, as well as in the soil from plots after pea cultivation than after durum wheat cultivation.

Highlights

The quality and chemical composition of post-harvest residues as well as the tillage system affect soils’ chemical properties and enzyme activity [1,2,3]
The content of total N was significantly higher in the soil from reduced tillage (RT) plots than in that from conventional tillage (CT) plots, as well as in soil from plots cultivated with pea than in soil from plots cultivated with durum wheat (Table 2)
Higher contents of N-NO3 and N-NH4 were determined in the soil from CT plots than in that from RT plots, as well as in the soil from plots submitted to pea cultivation than in the soil from plots cultivated with durum wheat (Table 3)

Summary

Introduction

The quality and chemical composition of post-harvest residues as well as the tillage system affect soils’ chemical properties and enzyme activity [1,2,3]. In soil cultivated according to the no-till system, the contents of organic carbon, total nitrogen, and nutrients are higher than in soil cultivated according to the conventional ploughing system [4,5,6,7]. Demonstrated that the soil subjected to a crop rotation system was characterized by higher activities of dehydrogenases, phosphatases, and ureases compared to soil subjected to monoculture. A higher enzyme activity (of dehydrogenases, phosphatases, and proteases) in soil was reported for the zero-tillage compared to the conventional tillage. According to Roldán et al [9], dehydrogenases occur commonly in soils rich in organic matter, their activity is indicative of the intensity of the respiratory metabolism of microorganisms. Phosphatases stimulate the transformation of the organic compounds of phosphorus into inorganic phosphates [10], whereas ureases take part in the process of ammonification, namely, the release of ammonia from urea, amino acids, and purine bases [11]

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Conclusion