Soil pH, nitrogen, phosphatase and urease activities in response to cover crop species, termination stage and termination method

Abstract

The best management options for cover cropping are largely unknown, including the growth patterns of cover crop (CC) species, optimum termination stages and termination methods. A greenhouse experiment was conducted to explore the following: (i) Effect of two termination stages (vegetative and flowering) on the chemical composition (N and C:N) of four CCs; (ii) Short-term impacts of living CCs and residues on soil pH, total N, urease and phosphatase activities at the two termination stages, and under two termination methods (slash and spray). Species tested as CCs were, vetch ( Vicia dasycarpa L.), field pea ( Pisum sativum L.), oats ( Avena sativa L.), rye ( Secale cereal L.) and a control (no CC). The experiment was set up in a randomized block design with three replications. Soil was sampled at kill and one year after CC kill. Delaying termination from vegetative till flowering stage decreased N in the tissue of P. sativum , A. sativa , V. dasycarpa and S. cereal by 59%, 65%, 44% and 56%, respectively, while their C:N ratios increased. Cover crop presence had no effect on soil pH. Living CCs had no significant effect on soil N concentration. The activities of urease and phosphatase were stimulated by all the living CC species. Unlike urease, all CC residues had a positive impact on phosphatase activity at one year. Only P. sativum and V. dasycarpa residues increased soil N concentration in the short-term. Compared to flowering, termination at vegetative stage improved soil N concentrations and phosphatase activity at both sampling times. Termination method had no effect on soil N, urease and phosphatase activity at one year. The significant interaction ( P < 0.05) of sampling time, CC and termination stage effects on soil N concentration and phosphatase activity observed in this study indicates that these management approaches can optimize CC benefits and improve soil chemical and biological properties.

The Effect of Alfalfa Mineral Fertilization and Times of Soil Sampling on Enzymatic Activity

“…Additionally, the activity of other enzymes determined in the present research proved the intensive mineralization of organic compounds in soil. This finding has been confirmed by other studies [1,7,[31][32][33]. Enzymatic activity in soil is related to its high content of organic carbon (Table 1), total and mineral nitrogen [6,13,34].…”

“…It should be added that these studies used soils with optimal chemical properties (pH, Ctot content, content of available forms of nitrogen, phosphorus, potassium, and magnesium). Urease and phosphatase activity decreased over time with no significant differences between chemical composition of soil residues and the control [1]. Despite the applied mineral fertilizer treatment, Harasim et al [10] recorded urease and dehydrogenases activity many times lower.…”

“…According to Adetunji et al [1], urease and phosphatase activities were stimulated by all crop species. Unlike urease, all crop residues had a positive impact on phosphatase activity at one year.…”

“…In recent years, there has been an increasing interest in growing legumes as cultivated plants. Mineral fertilization of leguminous plants significantly differentiates the enzymatic activity of soil as well as the quality and quantity of the yield [1][2][3].…”

Regulating Root Fungal Community Using Mortierella alpina for Fusarium oxysporum Resistance in Panax ginseng

“…Total potassium and available potassium were determined by flame atomic absorption spectrophotometry ( Li et al, 2021a ), and organic matter was determined by the loss-of-burning method ( Salehi et al, 2011 ). Soil urease activity was determined by indophenol colorimetry ( Adetunji et al, 2021 ), and the activities of soil catalase, acid phosphatase, and sucrase were determined using kits (Suzhou Grace Biotechnology Co. Ltd.; Zhou et al, 2020 ).…”