Nitrogen Management Strategies of Tillage and No-Tillage Wheat Following Rice in the Yangtze River Basin, China: Grain Yield, Grain Protein, Nitrogen Efficiency, and Economics

Abstract

In the rice-wheat rotation system, conventional culturing of high yield rice results in poor soil conditions and excessive residues, which negatively affect wheat growth. Tillage and nitrogen (N) use are being sought to address this problem. In order to propose a suitable tillage method and corresponding N management strategy, the influence of three tillage methods (i.e., plow tillage followed by rotary tillage (PR), rotary tillage twice (RR), and no-tillage (NT)) and nine forms of N management strategies (i.e., three total N rates × three N-splitting schemes) were investigated in a field experiment from 2016 to 2017 (2017) and 2017 to 2018 (2018), using grain yield, grain protein content (GPC), N uptake efficiency (NUpE), and net returns as evaluation indexes. Grain yield, GPC, and net returns were lower in 2017 than 2018, likely as a result of weak seedling growth caused by high soil moisture before and after seeding. In 2017, NT achieved higher grain yield, NUpE, and net returns compared to PR or RR, while grain yield and net returns were higher under tillage in 2018, especially PR. Increased total N rates (210–270 kg ha−1) promoted all evaluation indexes, but suitable timing and corresponding rates of N application are dependent on the environment. These results indicate that the combination of NT and applying N at lower rates and only a few times (i.e., 168 and 72 kg ha−1 applied at pre-sowing and when flag leaves are visible) when the soil is not suitable for tillage is the best method for cutting costs and improving benefits. Under suitable conditions for tillage, PR and intensive management strategies (i.e., 135, 27, 54, and 54 kg ha−1 applied at pre-sowing, four-leaf, jointing, and booting, respectively) could be adopted to increase overall yield, quality, and benefits.

Tillage and seeding strategies for wheat optimizing production in harvested rice fields with high soil moisture

“…In this study, similar results were found; NUpE was higher under zero tillage than under rotary tillage when wheat was planted in harvested rice fields with high soil moisture (Table 6). It has been reported in previous studies that high NUpE is closely related to greater N accumulation, especially high N uptake after anthesis [34][35][36][37][38] . Some reports have indicated that N uptake during the early growth phase is not directly associated with NUpE 37,39,40 .…”

“…Rial-Lovera et al 33 reported that tillage influenced N use efficiency in a humid growing season. Ding et al 34 found that zero tillage achieved a higher NUpE than tillage under excessive soil moisture conditions during the early growth stage, and that there was no difference when the soil moisture was suitable for tillage. In this study, similar results were found; NUpE was higher under zero tillage than under rotary tillage when wheat was planted in harvested rice fields with high soil moisture (Table 6).…”

“…However, it has also been reported that conventional tillage increases the productivity of RWRSs compared to zero tillage 46 . Ding et al 34 considered that tillage is better than zero tillage for increasing grain yields and net returns when the soil moisture is suitable for tillage, but zero tillage facilitates the achievement of higher yield and benefits. Thus, the grain yield, as affected by the tillage method, is the determining factor underlying the economic benefit.…”

Wheat Quality Formation and Its Regulatory Mechanism

“…In wheat production, fertilization and watering strategies are also often considered for quality improvement ( Li et al, 2018 , 2019b ; Yu et al, 2018a , 2021 ). As nitrogen (N) is one of the most important and essential elements for wheat, N fertilizer is usually the most efficient input for simultaneously increasing grain protein content and grain yield in wheat production ( Zebarth et al, 2007 ; Malik et al, 2013 ; Zhen et al, 2018 , 2020 ; Zhong et al, 2018 , 2020 ; Ding et al, 2020 ; Xia et al, 2020 ; Hermans et al, 2021 ; Landolfi et al, 2021 ; Lyu et al, 2021 ; Dong et al, 2022 ; Liu et al, 2022 ; Ma et al, 2022 ). Kichey et al (2007) demonstrated that 50–95% of nitrogen in mature grains is derived from the remobilization of nitrogen stored in the tissues before anthesis.…”

“…Furthermore, a delay of N topdressing was found to alter the grain hardness and flour allergenicity ( Zhong et al, 2019 ). Ding et al (2020) found that an increase in total N provision (210–270 kg ha −1 ) in the Yangtze River basin of China could enhance wheat grain yield, grain protein content, and nitrogen efficiency, with the appropriate topdressing timing and N application dose depending on the environment. Moreover, the biotic and abiotic stresses during wheat growth also significantly affect the quality of wheat ( Duan et al, 2020 ).…”