Nitrogen Loss by Erosion From Mechanically Tilled and Untilled Soil Under Successive Simulated Rainfalls

Abstract

the description of the fate of fertilizer-derived nitrogen (N) in agricultural systems is an essential tool to enhance management practices that maximize nutrient use by crops and minimize losses. soil erosion causes loss of nutrients such as N, causing negative effects on surface and ground water quality, aside from losses in agricultural productivity by soil depletion. studies correlating the percentage of fertilizer-derived N (fdN) with soil erosion rates and the factors involved in this process are scarce. the losses of soil and fertilizer-derived N by water erosion in soil under conventional tillage and no tillage under different rainfall intensities were quantified, identifying the intervening factors that increase loss. The experiment was carried out on plots (3.5 × 11 m) with two treatments and three replications, under simulated rainfall. the treatments consisted of soil with and soil without tillage. three successive rainfalls were applied in intervals of 24 h, at intensities of 30 mm/h, 30 mm/h and 70 mm/h. the applied N fertilizer was isotopically labeled ( 15 N) and incorporated into the soil in a line perpendicular to the plot length. tillage absence resulted in higher soil losses and higher total nitrogen losses (tN) by erosion induced by the rainfalls. the fdN losses followed another pattern, since fdN contributions were highest from tilled plots, even when soil and tN losses were lowest, i.e., the smaller the amount of eroded sediment, the greater the percentage of fdN associated with these. rain intensity did not affect the fdN loss, and losses were greatest after less intense rainfalls in both treatments.

Agricultural Expansion in the Brazilian Cerrado: Increased Soil and Nutrient Losses and Decreased Agricultural Productivity

“…Little is known about how the loss of soil, nutrients, and agricultural productivity has changed over the years in the Cerrado [32][33][34][35][36][37]. Some studies of soil loss have been made on the medium to small scale or in plots [32,33,[35][36][37]; however, they do not give an overview of degraded soils in a large ecosystem scale or point out the main activities that cause soil degradation. Studies which consider a geospatial analysis, including applications using GIS, remote sensing, and the RUSLE model are sparse and cover limited areas within the Cerrado.…”

“…Few studies exist on the potential decrease in productivity caused by water erosion [38]. Additionally, little data exists on nutrient dynamics in eroding landscapes, despite the importance of nutrients for primary production [35]. Therefore, taking into account those reasons and addressing the challenge of food security, soil degradation, and the importance of the Cerrado for meeting future agricultural production, the main goal of this study is to obtain an overview of the loss of soil, agricultural productivity, and nutrients caused by water erosion in the Brazilian Cerrado between 2000 and 2012.…”

Effect of Losing Nitrogen Fertilizers on Living Organism and Ecosystem, and Prevention Approaches of their Harmful Effect

“…It is reported that nitrogen fertilizers are lost greatly from tilled soil plots, and the intensity of the rains impact the soil losses quantity. The nitrogen fertilizers losses were less on untilled plots [24]. Soluble nutrients such as nitrate and potassium can be lost in runoff and drainage water, whereas less soluble nutrients such as phosphorus can be lost with sediments moving in eroding soil and runoff water [25].…”

Nitrogen and phosphorus transport as a criterion for soil categorisation

“…However, soil management can significantly influence the soil nitrogen loss. Bramorski et al (2015) reported that the absence of soil tillage led to higher soil erosion and higher total nitrogen losses mainly in organic form and associated with the finer soil minerals. On the other hand, the losses of fertiliser-derived N from tilled soil plots were higher.…”