کاربرد کمپوست و کود سوپر فسفات تریپل برای بهبود فعالیت میکروبی و آنزیمی خاک و رشد ذرت در خاک لسی

کاربرد همزمان کمپوست غنی‌شده با کودهای شیمیایی منجر به افزایش فعالیت میکروبی خاک و قابلیت دسترسی عناصر غذایی می گردد. بنابراین آزمایشی با هدف تعیین اثر کمپوست و سوپرفسفات تریپل (tsp) بر فسفر قابل استفاده، ویژگی‌های بیوشیمیایی خاک و رشد گیاه ذرت به اجرا درآمد. آزمایش به صورت فاکتوریل در قالب طرح کاملا تصادفی در سه تکرار و در مجموع 36 نمونه در خاک کشت شده و گرماگذاری شده اجرا گردید. تیمارها در هر دو خاک کشت شده و گرماگذاری شده شامل سه سطح کمپوست (c0 فاقد کمپوست، c1 2 درصد وزنی وزنی کمپوست ساده و c2 2 درصد وزنی وزنی کمپوست غنی شده)، چهار سطح کودtsp (0، 10، 40 و 100 میلی‌گرم بر کیلوگرم) بودند. یافته‌های به دست آمده از این پژوهش نشان داد که استفاده از کمپوست یا tsp به تنهایی و نیز کاربرد همزمان آنها ویژگی‌های اندازه گیری شده در خاک ( فسفر قابل دسترس، کربن زیست‌توده میکروبی، تنفس ناشی از بستره، فعالیت آنزیم‌های فسفاتاز اسیدی، فسفاتاز قلیایی، اوره‌آز و کاتالاز) را بهبود بخشیده و رشد گیاه را افزایش داد. تیمار c2p3 بیشترین مقدار فسفر قابل دسترس، کربن زیست‌توده میکروبی، تنفس ناشی از بستره، کاتالاز و اوره‌آز را در خاک کشت شده (به ترتیب 23، 270، 93، 68 و 1.8 درصد) و گرماگذاری شده (به ترتیب 18، 243، 90، 53 و 1.2 درصد) به همراه داشت. افزودن کمپوست و tsp به خاک لسی مورد مطالعه با ماده آلی کم منجر به بهبود تنش تغذیه‌ای، فعالیت‌های میکروبی، آنزیمی خاک و افزایش رشد گیاه گردد.

using compost and triple superphosphate fertilizer to promote soil microbial and enzymatic properties and maize plant growth in loess soil

introduction plant growth and crop productivity may be adversely affected under unfavorable environmental conditions, such as a lack of organic matter in the soil. to counteract the negative impacts of these challenges, a unique strategy is required. the paucity of organic inputs, which is common in conventional agricultural production, can lead to soil degradation, erosion, and loss of soil organic matter, which are unfortunate consequences. soil organic amendments have been shown to have beneficial effects on crop production and a wide range of soil properties in agricultural systems. however, the limited availability of phosphorus (p) in soil can significantly restrict crop growth and productivity, particularly in maize crops. adequate p supply has been found to enhance early maturity, crop quality, and yield. however, the prolonged use of chemical fertilizers such as npk has been found to have adverse effects on soil fertility and crop quality. as a result, the combined application of organic and chemical fertilizers has been proposed as an effective approach compared to the single application of organic or chemical fertilizer alone. therefore, this study aimed to assess the potential benefits of using compost and triple super phosphate fertilizer (tsp) application on the chemical and biological properties of soil, as well as the properties of forage maize (cv. sc704), in loess soil.materials and methods a factorial experiment was conducted using a completely randomized design with three replications. a total of 36 samples were performed in two separate cultivated and incubated experiments. a pot experiment was conducted to invwstigate the effects of simple and enriched compost, containing urea and streptomyces, and varying amounts of tsp fertilizer (0, 10, 40, and 100 mg/kg), on soil properties and maize plant growth. in addition, an incubation experiment was conducted to measure the effects of the same treatments on soil microbial biomass and activity. the effect of treatments were analyzed as factorial under a completely randomized design. the biomass of maize plants was measured at the time of harvesting (the time from planting to harvesting of forage maize was 80 days). some parameters such as available phosphorus, substrate induced respiration, microbial biomass carbon, and some enzyme activity (acid phosphatase, alkaline phosphatase, catalase and urease) were measured in soil.results and discussion the findings of this study indicated that the application of compost and tsp fertilizer had significant effects on plant biomass. specifically, compost application led to an increase in microbial biomass carbon and enzymes activity (acid phosphatase, alkaline phosphatase, catalase and urease) in the soil, ultimately promoting plant growth. moreover, the combined application of compost and tsp fertilizer increased the availability of phosphorus, substrate induced respiration, and microbial biomass carbon in the soil. based on the findings, the combined application of tsp and compost resulted in further increases in substrate induced respiration (63 168%), microbial biomass carbon (72 167%), available phosphorus (29 103%), and enzyme activity (acid phosphatase (4 21), alkaline phosphatase (14 34%), catalase (13 32%), and urease(54 159%)) compared to the application of each amendment alone. this suggests that the addition of both tsp and compost promotes the availability of easily accessible nutrients for microbial growth and soil enzymes (acid phosphatase, alkaline phosphatase, catalase and urease) activity. the highest amount of available phosphorus, microbial biomass carbon, substrate induced respiration, catalase activity and urease activity in cultivated soil (23%, 270%, 93%, 68%, 1.8%, respectively) and incubated soil (18%, 243%, 90%, 53%, 1.2%, respectively) were observed in c2p3 treatment. the results also indicated that the enriched compost+tsp treatment led to the highest substrate induced respiration and microbial biomass carbon, followed by simple compost+tsp, enriched compost only, simple compost only, tsp fertilizer only, and the control. the increase in enzyme activity (p<0.01, r=0.90), and available phosphorus (p<0.01, r=0.60) in the soil positively influenced plant growth. specifically, the simultaneous application of compost and tsp had a greater effect on maize plant biomass. the highest root biomass (2.80 g), stem biomass (10.4 g), and leaf biomass (2.27 g) were observed in the enriched compost and 100 mg kg 1 tsp treatment, which differed significantly from the other treatments.conclusion the results of this study demonstrated that the addition of compost and tsp to loess soils can promote microbial biomass carbon, substrate induced respiration, enzyme activity (acid phosphatase, alkaline phosphatase, catalase, and urease), available phosphorus, and maize plant growth. moreover, the use of compost can protect soil microbial and enzymatic activities in loess soils. thus, the simultaneous application of enriched compost with tsp can reduce the use of chemical fertilizers and their negative environmental impacts.