نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 گروه علوم و مهندسی خاک، دانشکده کشاورزی، دانشگاه ملایر، ملایر، ایران.
2 گروه علوم و مهندسی خاک- دانشکده کشاورزی - دانشگاه ملایر- ملایر- همدان- ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and purpose: Enzyme activity evaluation is useful for determining soil microbial activity that are responsible for important reactions such as soil mineralization and homogenization of soil organic matter. Enzyme activity affects the physicochemical properties of soil and supports the growth of plants. Therefore, enzyme activity is a sensitive index to evaluate the effect of soil conditioners. Biochar is one of these organic modifiers whose use in soil can affect the enzymatic activity of soil. Therefore, the aim of this study is to investigate the effect of grape waste biochar, brown walnut shell and poultry manure on the enzymatic behavior of a clay loam soil.
Materials and methods: In order to conduct this research, a completely randomized experiment was conducted in three replications. Biochars were used in 10 percent by weight. The experimental treatments included control soil (CS), soil + grape waste biochar (GSB), soil + brown walnut shell biochar (NSB) and soil + poultry manure biochar (PMB). The samples were kept for about two months at a temperature of 25±3 degrees Celsius. During the incubation period, the humidity was maintained at 70% of the agricultural capacity by adding distilled water and mixing the samples. Soils were sampled after 5, 10, 30 and 60 days, and invertase, acid and alkaline phosphatase, and urease activities were measured in the samples.
Findings: The results showed that adding biochar to the soil increased the activity of invertase enzyme, which was 23, 15 and 8% higher in PMB, GSB and NSB treatments than the control treatment. The highest activity of alkaline phosphatase enzyme was observed in the control treatment and the lowest in the PMB treatment, and the activity of this enzyme in the PMB treatment was about 39% lower than the control soil. The order of alkaline phosphatase activity in different treatments was as follows: CS≥ GSB> NSB> PMB. Acid phosphatase activity in treated soils was completely opposite to invertase enzyme activity. The lowest activity was observed in the PMB treatment, which was about 67% less than the control treatment. The order of activity of this enzyme in different treatments was as follows: CS> NSB> GSB≥ PMB. The activity of urease enzyme in different treatments was similar to that of invertase enzyme. The peak activity of this enzyme was observed in the PMB treatment, which was about 71% more than the control treatment. Invertase enzyme activity in GSB and NSB treatment was 40% and 20% higher than the control treatment, respectively. On average, the geometric mean of enzyme activity increased during incubation in GSB treatment compared to the control. According to the enzyme resistance index, the lowest rate was related to PMB treatment and the highest rate was related to NSB treatment.
Conclusion: Considering that GSB treatment has an increasing effect on enzyme activity, especially carbon and nitrogen cycle enzymes. This organic modifier can be used as a supplementary source for supplying carbon and nitrogen elements to improve soil quality.
کلیدواژه‌ها [English]
)