Objectives This study compared the fine root traits of peach trees under drip fertigation and conventional fertilization to provide a basis for further improving the efficiency of drip fertigation technology.
Methods We studied the growth dynamics of fine roots of peach trees in a field experiment conducted at Zhongmu Experimental Base, Henan Province. The study was carried out for three years consecutively, taking 2-year-old peach trees as test materials. Drip fertigation (FG) and conventional fertilization (TF) were set up, with 40%–60% less NPK input in FG than TF. The minirhizotron of 70 cm long and 70 mm diameter was buried 40 cm deep and 60 cm away from the peach trees to monitor fine root number, lifespan, pigmentation, and standing crop, while the turnover rate was estimated. After leaf shedding in 2018, peach tree samples were collected, and the 15N tracer technique was used to measure the N uptake and allocation. Further, soil samples were collected to determine NH4+-N and NO3–-N contents.
Results Fine root population and traits were significantly different between TF and FG (P<0.05) . The fine roots in TF took 38 days to become pigmented, with a median lifespan of 107 days and a standing root of 82. These indexes were 51 days, 147 days, and 311 in FG. The number of standing roots decreased by year; the fine roots turnover rate in FG was markedly lower than TF across the three years. In late August, the root activity was 39.47 mg/(g·h) in FG and 27.86 mg/(g·h) in TF. In late November, peach roots in both treatments were in procession of dormancy, with no root activity difference. The Ndff amount in each part of the peach tree under FG was higher than TF (P<0.05) . The nitrogen utilization rate in FG (17.89%) was significantly higher than in TF (9.75%).
Conclusions Drip fertigation promoted fine root emergence, prolonged the lifespan and inter-year turnover rate, increased the number of standing roots, the root activity in growing seasons, and nitrogen uptake and utilization rate.
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