The dynamics of nitrogen derived from a chemical nitrogen fertilizer with treated swine slurry in paddy soil-plant systems

Abstract

A well-managed chemical nitrogen (N) fertilization practice combined with treated swine slurry (TSS) is necessary to improve sustainability and N use efficiency in rice farming. However, little is known about the fate of N derived from chemical N fertilizer with and without TSS in paddy soil-plant systems. The objectives of this study were (1) to estimate the contribution of applied N fertilizer to N turnover in rice paddy soil with different N fertilization practices that were manipulated by the quantity of treated swine slurry and chemical N fertilizer (i.e., HTSS+LAS, a high amount of TSS with a low amount of ammonium sulfate; LTSS+HAS, a low amount of TSS with a high amount of ammonium sulfate; AS, ammonium sulfate with phosphorus and potassium; C, the control) and (2) to compare the rice response to applied N derived from each N fertilization practice. Rice biomass yield, 15N recovery in both rice grain and stems, soil total N (TN), soil inorganic N, and soil 15N recovery were analyzed. Similar amounts of 15N uptake by rice in the TSS+AS plots were obtained, indicating that the effects of the different quantities of TSS on chemical fertilizer N recovery in rice during the experimental period were not significant. The soil 15N recoveries of HTSS+LAS, LTSS+HAS, and AS in each soil layer were not significantly different. For the HTSS+LAS, LTSS+HAS and AS applications, total 15N recoveries were 42%, 43% and 54%, respectively. Because the effects of reducing the use of chemical N fertilizer were attributed to enhancing soil quality and cost-effectiveness, HTSS+LAS could be an appropriate N fertilization practice for improving the long-term sustainability of paddy soil-plant systems. However, N losses, especially through the coupled nitrification-denitrification process, can diminish the benefits that HTSS+LAS offers.

Long Term Effects of Integrated Plant Nutrition System on Rice Yield, Nitrogen Dynamics and Biochemical Properties in Soil of Rice-rice Cropping System

“…The decreased N with the increase in soil depth in our study coincides with the results of Lee and Choi[5] and Rahman et al[43].…”

“…In this study the higher NO 3 concentration in the PM+IPNS treated soil might be due to higher NH 4 + concentration in this soil as the NH 4 + adsorbed onto clay particles is gradually converted to NO 3 via nitrification [5]. In an incubation study Murugan and Swarnam [59] found higher NO 3 in manure treated soils compared to inorganic N treated soils.…”

“…The lower concentration of NH 4 + -N in deeper soil layer might be attributed to its adsorbance on soil colloids which leads to lower percolation loss [57]. Lee and Choi [5]; Mi et al 2019 [58] also reported decreased NH 4 + -N with the increase of soil depth. As the mineralization of N from chemical N fertilizer is high the NH 4 + released from STB treatment is subjected to instant crop uptake [5] and volatilization loss which resulted in lower concentration of NH 4 + in the post harvested soil [52].…”

“…However, the intensive application of chemical N fertilizer in the cropping system has raised the concerns of sustainable crop production. Moreover, the injudicious use of chemical N fertilizer coupled with modern high yielding varieties and little or no use of organic matter lead to soil organic matter deficiency, soil acidity and impoverishment of the soil physical properties [3,4,5]. On the other hand, manure alone cannot substitute inorganic fertilizer to maintain the desired level of yield of the high yielding varieties [6].…”