A Comparison of Nitrogen Transfer and Transformation in Traditional Farming and the Rice–Duck Farming System by 15N Tracer Method

Abstract

A field experiment was conducted in Ninghe, Tianjin, China, using the 15N isotope method to determine the fate of N sources, application effect of organic fertilizer on the growth of rice plant organs, N uptake by rice, and N use efficiency. The experiment included eight treatments: CK-N (control + no-duck), CK-D (control + ducks), CF-N (chemical fertilizer + no-ducks), CF-D (chemical fertilizer + ducks), CM-N (chemical fertilizer + organic fertilizer + no-ducks), CM-D (chemical fertilizer + organic fertilizer + ducks), CD-N (chemical fertilizer 30% off + organic fertilizer + no-ducks), and CD-D (chemical fertilizer 30% off + organic fertilizer + ducks). The results showed that the application of organic fertilizer whether CM or CD in grain and leaf significantly increased N concentration; leaf and root P concentrations over control (CK) and chemical fertilizer (CF). In contrast, straw and root N concentrations, including grain and straw P concentrations did not show any difference between duck and no-duck treatment. Moreover, non-significant differences were found in 15N fresh grain and husk concentration. Both organs ranged from 14.2–14.4 g·kg−1 and 6.2–6.3 g·kg−1, respectively. Likewise, N uptake and N use efficiency in fresh grain and husk were not significantly differed within duck and without duck treatment. However, N uptake in fresh grain and husk ranged at the rates of 54.90–93.69 and 6.43–11.04 kg ha−1 with duck and without duck treatment. N use efficiency in fresh grain and husk ranged from 21.55%–34.61% and 2.61%–4.24%, respectively. Overall organic fertilizer has a significant influence on rice growth and promotes crop productivity.

The influence of rice-duck farm soil on the nitrogen content of different varieties of japonica rice

“…That duck soil can increase the N content of rice plants is in accordance with the results of the preceding field experiment of Ebissa et al (2018). To our knowledge, no other study has so far compared the N content of rice plants produced by rice-duck and conventional farming, but other related parameters have been studied.…”

“…In the duck field, twenty ducks were released at the vegetative stage in 2017. Soil samples for soil characterization were collected from each field using an auger in October 2017 as described in Ebissa et al (2018). For the purpose of the present study, only the 0-20 cm layer was sampled, yielding three samples from each of four plots in both the duck and no-duck fields (n = 12 per treatment).…”

“…The soil samples were air-dried, ground and sieved to pass through a 0.15-mm mesh. The following soil properties were evaluated: pH, total N, NO 3 − , NH 4 + , soil organic matter, total P and particle size distribution, as described in Ebissa et al (2018) (Table 2).…”

“…Understanding the mechanisms by which ducks influence rice plants in paddy fields is necessary to continue improving rice-duck farming systems towards higher N use efficiency. For example, rice-duck farming can induce higher N content in certain rice organs (Ebissa et al 2018). Several direct and indirect pathways are proposed for why ducks influence rice growth, based on field observations of rice-duck farming and conventional rice cultivation.…”

Effects of organic amendments on soil bacterial community structure and yield in a saline‐sodic soil cropped with rice

“…In recent years, it has been adapted and applied to rice fields in saline‐sodic land management. Operating as a relatively closed system in rice‐duck farming, the use of duck manure as a nutrient source to maintain rice growth promotes the accumulation of SOM and nitrogen (Ebissa et al, 2018). Simultaneously, the activities of duck flocks alter soil structure, improve soil permeability and redox potential (Xu et al, 2017), and facilitate the growth and development of rice roots (Teng et al, 2016).…”