Root-zone fertilization improves crop yields and minimizes nitrogen loss in summer maize in China.
Jiang Chaoqiang,Lu Dianjun,Zu Chaolong,Zhou Jianmin,Wang Huoyan
Scientific reports
It is urgently to minimize nitrogen (N) loss while simultaneously ensuring high yield for maize in China. A two-year field experiment was conducted to determine the effects of root-zone fertilization (RZF) and split-surface broadcasting (SSB) on grain yield, N use efficiency (NUE), and urea-N fate under different N rates (135, 180 and 225 kg ha). Results showed that RZF increased grain yield by 11.5%, and the N derived from fertilizer (Ndff%) by 13.1-19.6%, compared with SSB. The percentage of residual N in the 0-80 cm soil was 37.2-47.4% after harvest; most N (64.4-67.4%) was retained in the top 20 cm. RZF significantly increased the N apparent recovery efficiency (NARE) and N recovery in maize by 14.3-37.8% and 21.9-30.0%, respectively; while decreased N losses by 11.2-24.2%, compared with SSB. The RZF of urea can be considered a slow-release fertilizer, which better matches maize N demand and effectively reduces N losses. Overall, RZF achieved yields as high as the SSB, but with a 20-25% reduction in N application. These results help improve our understanding of N fate in the maize cropping system, and may help guide recommendations for N management in southeastern China.
10.1038/s41598-018-33591-9
Effects of root-zone acidity on utilization of nitrate and ammonium in tobacco plants.
Journal of plant nutrition
Tobacco (Nicotiana tabacum L., cv. 'Coker 319') plants were grown for 28 days in flowing nutrient culture containing either 1.0 mM NO3- or 1.0 mM NH4+ as the nitrogen source in a complete nutrient solution. Acidities of the solutions were controlled at pH 6.0 or 4.0 for each nitrogen source. Plants were sampled at intervals of 6 to 8 days for determination of dry matter and nitrogen accumulation. Specific rates of NO3- or NH4+ uptake (rate of uptake per unit root mass) were calculated from these data. Net photosynthetic rates per unit leaf area were measured on attached leaves by infrared gas analysis. When NO3- [correction of NO-] was the sole nitrogen source, root growth and nitrogen uptake rate were unaffected by pH of the solution, and photosynthetic activity of leaves and accumulation of dry matter and nitrogen in the whole plant were similar. When NH4+ was the nitrogen source, photosynthetic rate of leaves and accumulation of dry matter and nitrogen in the whole plant were not statistically different from NO3(-) -fed plants when acidity of the solution was controlled at pH 6.0. When acidity for NH4(+) -fed plants was increased to pH 4.0, however, specific rate of NH4+ uptake decreased by about 50% within the first 6 days of treatment. The effect of acidity on root function was associated with a decreased rate of accumulation of nitrogen in shoots that was accompanied by a rapid cessation of leaf development between days 6 and 13. The decline in leaf growth rate of NH4(+) -fed plants at pH 4.0 was followed by reductions in photosynthetic rate per unit leaf area. These responses of NH4(+) -fed plants to increased root-zone acidity are characteristic of the sequence of responses that occur during onset of nitrogen stress.
10.1080/01904168909363995
Chloride Improves Nitrate Utilization and NUE in Plants.
Frontiers in plant science
Chloride (Cl) has traditionally been considered harmful to agriculture because of its toxic effects in saline soils and its antagonistic interaction with nitrate (NO ), which impairs NO nutrition. It has been largely believed that Cl antagonizes NO uptake and accumulation in higher plants, reducing crop yield. However, we have recently uncovered that Cl has new beneficial macronutrient, functions that improve plant growth, tissue water balance, plant water relations, photosynthetic performance, and water-use efficiency. The increased plant biomass indicates in turn that Cl may also improve nitrogen use efficiency (NUE). Considering that N availability is a bottleneck for the plant growth, the excessive NO fertilization frequently used in agriculture becomes a major environmental concern worldwide, causing excessive leaf NO accumulation in crops like vegetables and, consequently, a potential risk to human health. New farming practices aimed to enhance plant NUE by reducing NO fertilization should promote a healthier and more sustainable agriculture. Given the strong interaction between Cl and NO homeostasis in plants, we have verified if indeed Cl affects NO accumulation and NUE in plants. For the first time to our knowledge, we provide a direct demonstration which shows that Cl, contrary to impairing of NO nutrition, facilitates NO utilization and improves NUE in plants. This is largely due to Cl improvement of the N-NO utilization efficiency (NUE), having little or moderate effect on N-NO uptake efficiency (NUE) when NO is used as the sole N source. Clear positive correlations between leaf Cl content vs. NUE/NUE or plant growth have been established at both intra- and interspecies levels. Optimal NO vs. Cl ratios become a useful tool to increase crop yield and quality, agricultural sustainability and reducing the negative ecological impact of NO on the environment and on human health.
10.3389/fpls.2020.00442
Evolution trend of soil fertility in tobacco-planting area of Chenzhou, Hunan Province, China.
Open life sciences
In this study, the data of fertility indicators of soil samples (0-20 cm) in 1980s, 2000 and 2015 in Chenzhou city were used, and the soil integrated fertility index (IFI) was calculated. The results showed that the soil pH was decreased, total nitrogen (TN), organic matter (OM), available phosphorus (AP) and potassium (AK), exchangeable calcium (Ca), magnesium (Mg) and available copper (Cu) contents were increased, total phosphorus (TP), available sulfur (S) and water-soluble chlorine (Cl) contents were decreased, total potassium (TK), available boron (B), iron (Fe), manganese (Mn) and zinc (Zn) were decreased first and then increased. In 2015, most of the fields were higher in pH, OM, TN, AN, AK, Ca, Mg, S, Fe, Mn, Cu and Zn, suitable in B, but lower in TP, AP, TK, available molybdenum (Mo) and Cl. Most of the fields were in the middle grade of IFI in 2000 and 2015, and the mean IFI increased from 0.492 to 0.556 from 2000 to 2015. Thus, for soil improvement, more attention should be paid to adjust soil pH, reduce the application of organic, nitrogen and calcium fertilizers, while increase the fertilizer application of other nutrients.
10.1515/biol-2022-0509
Deciphering the impact of nitrogen morphologies distribution on nitrogen and biomass accumulation in tobacco plants.
Frontiers in plant science
Background and aims:Nitrogen (N) distribution in plants is intricately linked to key physiological functions, including respiration, photosynthesis, structural development, and nitrogen storage. However, the specific effects of different N morphologies on N accumulation and plant growth are poorly understood. Our research specifically focused on determining how different N morphologies affect N absorption and biomass accumulation. Methods:This study elucidated the impact of different application rates (CK: 0 g N/plant; T1: 4 g N/plant; T2: 8 g N/plant) of N fertilizer on N and biomass accumulation in tobacco cultivars Hongda and K326 at different growth stages. Results:Our findings emphasize the critical role of N distribution in various plant parts, including leaves, stems, and roots, in determining the complex mechanisms of N and biomass accumulation in tobacco. We found that in relation to total N, a greater ratio of water-soluble N ( ) in leaves facilitated N accumulation in leaves. In contrast, an increased ratio of SDS (detergent)-insoluble N ( ) in leaves and non-protein N ( ) in roots hindered this increase. Additionally, our results indicate that a greater proportion of in leaves has a negative impact on biomass accumulation in leaves. Furthermore, elevated levels of , , and in roots, and in leaves adversely affected biomass accumulation in tobacco leaves. The Hongda cultivar exhibited greater biomass and N accumulation abilities as compared to K326. Conclusions:Our findings highlight the significant role of distribution of N morphologies on plant growth, as well as N and biomass accumulation in tobacco plants. Understanding N distribution allows farmers to optimize N application, minimizing environmental losses and maximizing yield for specific cultivars. These insights advance sustainable agriculture by promoting efficient resource use and reducing environmental impact.
10.3389/fpls.2024.1377364