Effect of crop rotation on nitrogen leaching with the lysimetric waters in vulnerable areas

Abstract

Abstract. Climate change is known to subject the functioning of agroecosystems to high levels of biotic and abiotic stress and has a significant impact on agricultural production worldwide. Crop rotation is believed to be one way of adapting agriculture to climate change compared to monoculture This study aimed to examine the maize-wheat rotation impact on soil nitrogen dynamics and leaching losses. A study has been carried out on the experimental field of Tsalapitsa, Plovdiv region on Fluvisol. In this maize-wheat rotation experiment, we compared three fertilization treatments with increasing nitrogen and phosphorus rates to a control with no fertilization. In 2020, grain maize (Zea mays L.) FAO group 310, was grown with fertilizer rates (T0N0P0; T1N120P80; T2N160P120; T3N200P160). In the period 2020/2021, wheat, (Triticum aestivum L.), was grown with the following fertilizer variants – (Т0 N0P0; Т1N100P60; Т2 N140P100; Т3 N180P140). The field plots were equipped with modification of Ebermayer type of lysimeters, which collect water from 100 cm depth of soil profile. The volume of lysimetric waters was calculated, the nitrogen content and its leaching were analyzed. The study found that the lysimetric water volume after maize cultivation was 75.95 liters per square meter, approximately 2.5 to 3 times higher than that observed after wheat cultivation. Nitrogen content varied with fertilization rates, ranging from 10.8 to 37.5 mg/L for maize and 8.73 to 23.58 mg/L for wheat. The losses of the element with drainage runoff with the first crop were – 5.6-28.5 kg.ha-1, and with wheat – 1.2-6.3 kg.ha-1, respectively. It was established that when cereal crops were grown the losses of nitrate nitrogen out of the root zone were significantly reduced.