N2 Treatment Research Articles

Effects of water-nitrogen interactions on NH3 and N2O emissions and yield in winter wheat cropland

To investigate the effects of different irrigation and nitrogen application modes on nitrogen gaseous loss in winter wheat farmland, we conducted a field experiment at Changqing Irrigation Experiment Station in Shandong Province, with two irrigation levels (80%-90% θf(I1) and 70%-80% θf(I2)) and three nitrogen application levels (conventional nitrogen application of 240 kg·hm-2(N1), nitrogen reduction of 12.5% (N2), and nitrogen reduction of 25% (N3)). The results showed that ammonia volatilization and nitrous oxide emission rate peak appeared within 2-4 days after fertilization or irrigation. The ammonia volatilization rate during the chasing fertilizer period was significantly higher than that during the basal fertilizer period. Compared with other treatments, the ave-rage ammonia volatilization rate of I2N2 treatment during the chasing fertilizer period was reduced by 10.1%-51.6%, and the average nitrous oxide emission rate over the whole growth period was reduced by 15.4%-52.2%. The ammonia volatilization rate was significantly positively associated with surface soil pH value and ammonium nitrogen content, while the nitrous oxide emission rate was significantly positively associated with nitrate content in topsoil. The accumulation amount of soil ammonia volatilization and nitrous oxide emission ranged from 0.83-1.42 and 0.11-0.33 kg·hm-2, respectively. Moderate reduction of irrigation water and nitrogen input could effectively reduce cumulative amounts of ammonia volatilization and nitrous oxide emission from winter wheat farmland. The cumulative amounts of ammonia volatilization and nitrous oxide emission under I1N3 and I2N2 treatments were signi-ficantly lower than those under other treatments. The highest winter wheat yield (5615.6 kg·hm-2) appeared in I2N2 treatment. The irrigation water utilization efficiency of I2 was significantly higher than that of I1, with the maximum increase rate of 45.2%. Compared with N1 and N3 treatments, the maximum increase rate of nitrogen fertilizer productivity and agricultural utilization efficiency in N2 reached 15.2% and 31.8%, respectively. In conclusion, the treatment with 70%-80% θf irrigation level and 210 kg·hm-2 nitrogen input could effectively improve the utilization efficiency of irrigation water and nitrogen fertilization and reduce gaseous loss from winter wheat farmland.

Optimizing Nitrogen Fertilizer Management Enhances Rice Yield, Dry Matter, and Nitrogen Use Efficiency

Optimizing nitrogen fertilizer management can effectively improve soil ecology, promote agricultural production, and increase the income of farmers and workers. Nitrogen fertilizer is an important factor in the growth and development of rice, and it is important to find out the optimal amount and frequency of fertilizer application for the super-hybrid early rice ‘Zhu LiangYou 819’ in Hunan Province, to give full play to its high quality and high yield characteristics. Various N fertilizer application frequencies (P1, basal–tiller fertilizer = 5:5; P2, basal–tiller–spike fertilizer = 4:3:3; P3, basal–tiller–spike–grain fertilizer = 4:3:2:1) and N application amounts (N1, 90 kg ha−1; N2, 150 kg ha−1; N3, 210 kg ha−1) were applied to the hybrid rice ZLY819. The results show that, under the same frequency of N application, ZLY819 had the highest yield, agronomic efficiency, and physiological utilization rate of N fertilizer with the N2 treatment, averaging 7.53 t ha−1, 18.10 kg kg−1, and 34.34%, respectively, with the yield under N2 being 19.38% higher than that under N1. For the same amount of N application, the yield, agronomic efficiency, partial factor productivity of N (PFPN), N contribution to seed, and N use efficiency (NUE) increased with an increase in the frequency of N application, mainly in the order of P3 > P2 > P1, whereby the yield of P3 was 10.11% higher than that of P1. According to the regression equation, the yield is higher when the amount of nitrogen application is 202.15 kg ha−1 and the fertilization frequency is four times. Appropriate N fertilizer management (P3N2) improved the rice growth characteristics, dry matter accumulation, crop growth rate, dry matter transport rate, dry matter contribution rate, and NUE, thus promoting an increase in the rice yield and efficient use of nitrogen.

Different nitrogen concentrations affect strawberry seedlings nitrogen form preferences through nitrogen assimilation and metabolic pathways

The preference for different forms of nitrogen (N) is an essential means to improve plant nitrogen utilization efficiency (NUE). Currently, little information is known about the N uptake preferences of strawberries and their interaction with N concentration. In this study, the preference and distribution of nitrate nitrogen (NO3−-N) and ammonium nitrogen (NH4+-N) in strawberry seedlings were investigated in response to different N concentrations. This study used two labeled N sources (15NH4NO3 and NH415NO3) for tracer labeling. Three levels of NH4NO3 were set: low N 5 mM (N1), medium N 15 mM (N2), and high N 25 mM (N3). Each N level included two 15N labeling treatments, totaling six treatments. The results showed that under low N, medium N, and high N conditions, strawberry seedlings exhibited preferences for NH4+-N, NO3−-N, and NH4+-N, respectively. Compared with N1 and N3 treatments, N2 treatment significantly increased the activity of NR, NiR, GS, and GOGAT in strawberry seedlings roots and leaves, and the relative expression levels of FaNRT1.1, FaNRT2.1, and FaAMT1.1 in roots were significantly upregulated; When the N supply concentration increases, the distribution center of NO3−-N in strawberry seedlings shifts from stem to leaf, and under high N conditions, NH4+-N accumulates significantly in the strawberry roots. According our research, the N assimilation and metabolic capacity of strawberries themselves are important factors affecting N form preferences.

Optimization of inter-seasonal nitrogen allocation increases yield and resource-use efficiency in a water-limited wheat–maize cropping system in the North China Plain

Winter wheat–summer maize cropping system in the North China Plain often experiences drought-induced yield reduction in the wheat season and rainwater and nitrogen (N) fertilizer losses in the maize season. This study aimed to identify an optimal interseasonal water- and N-management strategy to alleviate these losses. Four ratios of allocation of 360 kg N ha−1 between the wheat and maize seasons under one-time presowing root-zone irrigation (W0) and additional jointing and anthesis irrigation (W2) in wheat and one irrigation after maize sowing were set as follows: N1 (120:240), N2 (180:180), N3 (240:120) and N4 (300:60). The results showed that under W0, the N3 treatment produced the highest annual yield, crop water productivity (WPC), and nitrogen partial factor productivity (PFPN). Increased N allocation in wheat under W0 improved wheat yield without affecting maize yield, as surplus nitrate after wheat harvest was retained in the topsoil layers and available for the subsequent maize. Under W2, annual yield was largest in the N2 treatment. The risk of nitrate leaching increased in W2 when N application rate in wheat exceeded that of the N2 treatment, especially in the wet year. Compared to W2N2, the W0N3 maintained 95.2% grain yield over two years. The WPC was higher in the W0 treatment than in the W2 treatment. Therefore, following limited total N rate, an appropriate fertilizer N transfer from maize to wheat season had the potential of a “triple win” for high annual yield, WPC and PFPN in a water-limited wheat–maize cropping system.

Appropriate Nitrogen Application for Alleviation of Soil Moisture-Driven Growth Inhibition of Okra (Abelmoschus esculentus L. (Moench))

Uneven rainfall, in the context of global warming, can cause soil moisture fluctuations (SMFs) that harm crop growth, and it is not yet known whether nitrogen (N) can mitigate the harm caused by a strong SMF. This paper uses okra as a test subject and sets three SMFs of 45–55% FC (W1), 35–65% FC (W2), and 25–75% FC (W3) and three N applications of 0 kg hm−2 (N0), 110 kg hm−2 (N1), and 330 kg hm−2 (N2) to investigate the effects of SMF and N application on the physiological and biochemical aspects of okra. The results demonstrated that okra exhibited the highest values in stem diameter, number of leaves, photosynthesis characteristics, antioxidant enzyme activity, and yield under the N1 treatment. The average yield in the N1 treatment was 149.8 g, significantly surpassing the average yields of the N0 (129.8 g) and N3 (84.0 g) treatments. Stomatal density, antioxidant enzyme activity, malondialdehyde content, and proline content in okra leaves were highest in the W3 treatment, indicating that plants experienced stress in the W3 treatment. However, the agronomic traits and yields of okra in the N1 treatment were higher than those in the N0 and N1 treatments, indicating that the crop damage caused by W3 could be mitigated by an appropriate amount of N application. The N1W1 treatment emerged as the most suitable combination for okra growth in this study, exhibiting the highest stem diameter, leaf count, photosynthetic characteristics, and yield (201.3 g). Notably, this yield was 67.8% higher than the lowest treatment (N2W3), signifying a significant improvement.

Elemental mercury production from contaminated riparian soil suspensions under air and nitrogen bubbling conditions.

The dynamic change of redox conditions is a key factor in emission of elemental mercury (Hg0) from riparian soils. The objective of this study was to elucidate the influences of redox conditions on Hg0 emission from riparian soils. Soil suspension experiments were conducted to measure Hg0 emission from five Hg-contaminated soil samples in two redox conditions (i.e., treated with air or with N2). In four of the five samples, Hg0 emission was higher in air treatment than on N2 treatment. Remaining one soil, which has higher organic matter than other soils, showed no distinct difference in Hg0 production between air and N2 treatment. In soil suspensions subject to N2 treatment, the dissolved organic carbon (DOC) and Fe2+ concentrations were 3.38- to 1.34-fold and 1.44- to 2.28-fold higher than those in air treatment, respectively. Positive correlations were also found between the DOC and Fe2+ (r = 0.911, p < 0.01) and Hg2+ (r = 0.815, p < 0.01) concentrations in soil solutions, suggesting Fe2+ formation led to the release of DOC, which bound to Hg2+ in the soil and, in turn, limited the availability of Hg2+ for reduction to Hg0 in N2 treatment. On the other hand, for remaining one soil, more Hg2+ might be adsorbed onto the DOM in the air treatment, resulted in the inhibition of Hg0 production in air treatment. These results imply that the organic matter is important to prevent Hg0 production by changing redox condition. Further study is needed to prove the role of organic matter in the production of Hg0.

Effects of irrigation and fertilization with biochar on the growth, yield, and water/nitrogen use of maize on the Guanzhong Plain, China

Excessive water and nitrogen inputs in agricultural production can result in resource wastage and environmental pollution. This makes it imperative to identify effective farmland management strategies to ensure sustainable agriculture development, and it remains to be explored whether biochar can be an effective solution. In this study, a 2-year (2021 and 2022) field experiment was conducted with two irrigation levels, W100 (ET) and W80 (0.8 ET), and three nitrogen fertilizer levels, NH (270 kg ha−1), NM (180 kg ha−1), and NL (90 kg ha−1), in full combination with biochar (30 t ha−1). The NM and N0 treatments without biochar at both irrigation levels were set as controls. The results of the study showed that there was no significant difference in maize yield between the high and medium N treatments. Further, maximum water productivity (WP), nitrogen agronomic efficiency (NAE), and nitrogen recovery efficiency (NRE) were obtained in NM treatments when water and nitrogen were kept consistent. Deficit irrigation was effective in reducing water consumption and increased WP by 15.54% and 11.06% in 2021 and 2022, respectively. Biochar application increased WP, nitrogen use efficiencies, and significantly increased the yield by 7.02% and 6.46% in 2021 and 2022, respectively. Therefore, the application of biochar can be an effective measure to promote crop growth and resource use. Based on the results of this experiment, an irrigation level of 0.8 ET in combination with NM and biochar application is recommended to ensure the sustainability of agricultural production.

Post-anthesis dry matter and nitrogen accumulation, partitioning, and translocation in maize under different nitrate-ammonium ratios in Northwestern China.

An appropriate supply of ammonium (NH4+) in addition to nitrate (NO3-) can greatly improve plant growth and promote maize productivity. However, knowledge gaps exist regarding the mechanisms by which different nitrogen (N) fertilizer sources affect the enzymatic activity of nitrogen metabolism and non-structural carbohydrates during the post-anthesis period. A field experiment across 3-year was carried out to explore the effects of four nitrateammonium ratio (NO3-/NH4+ = 1:0 (N1), 1:1 (N2), 1:3 (N3), and 3:1 (N4)) on postanthesis dry matter (DM) and N accumulation, partitioning, transportation, and grain yield in maize. NO3-/NH4+ ratio with 3:1 improved the enzymatic activity of N metabolism and non-structural carbohydrate accumulation, which strongly promoted the transfer of DM and N in vegetative organs to reproductive organs and improved the pre-anthesis DM and nitrogen translocation efficiency. The enzymatic activities of nitrate reductase, nitrite reductase, glutamine synthetase, glutamine oxoglutarate aminotransferase, and non-structural carbohydrate accumulation under N4 treatment were increased by 9.30%-32.82%, 13.19%-37.94%, 4.11%-16.00%, 11.19%-30.82%, and 14.89%-31.71% compared with the other treatments. Mixed NO3--N and NH4+-N increased the total DM accumulation at the anthesis and maturity stages, simultaneously decreasing the DM partitioning of stem, increasing total DM, DM translocation efficiency (DMtE), and contribution of pre-anthesis assimilates to the grain (CAPG) in 2015 and 2017, promoting the transfer of DM from stem to grain. Furthermore, the grain yield increased by 3.31%-9.94% (2015), 68.6%-26.30% (2016), and 8.292%-36.08% (2017) under the N4 treatment compared to the N1, N2, and N3 treatments. The study showed that a NO3-/NH4+ ratio of 3:1 is recommended for high-yield and sustainable maize management strategies in Northwestern China.

Assessing vegetation indices and productivity across nitrogen gradients: a comparative study under transplanted and direct-seeded rice

Nitrogen responses vary under diverse agronomic management practices, influencing vegetation indices (VIs) and productivity across different ecological conditions. However, the proper quantification of these responses under various crop establishment methods with varied nitrogen levels is rarely studied. Therefore, a field experiment was conducted to investigate the impact of varying nitrogen levels on VIs, growth parameters, yield attributes, yield, and economic aspects of transplanted rice (TR) and direct-seeded rice (DSR). The experiment was conducted in the randomized block design consisted seven N levels, which included 0% recommended dose of nitrogen (RDN) or no nitrogen (N0), 33.33% RDN (N1), 66.66% RDN (N2), 100% RDN (N3), 133.33% RDN (N4), 166.66% RDN (N5) and 200% RDN (N6), and replicated thrice. The plots with higher N levels demonstrated increased values of VIs and treatment N3 (120 kg N ha−1), N4 (160 kg N ha−1), N5 (200 kg N ha−1), and N6 (240 kg N ha−1) showed no statistically significant differences in NDVI (normalized difference vegetation index), RVI (ratio vegetation index), NDRE (normalized difference red edge), and GNDVI (green normalized difference vegetation index) values across the various growth stages of rice. The application of treatment N4 resulted in the highest number of panicles m−2 (348.2 in TR, 376.8 in DSR), filled grains panicle−1 (74.55 in TR, 62.43 in DSR), and a 1,000-grain weight of 26.92 g in TR and 26.76 g in DSR. The maximum yield (4.89 t ha−1) was obtained in transplanted rice at treatment N4 and, 8.15% yield reduction was noted in DSR for the same treatment, which was statistically equivalent to N3, but significantly superior to other N levels. Conversely, in DSR with RDN (120 kg N ha−1), the cost–benefit ratio surpassed that of TR by 16.96%, signifying DSR’s adaptability for more profitable rice cultivation in the region. This research provides valuable insights into optimizing nitrogen management practices for TR and DSR, thereby enhancing rice crop performance and economic returns.

Effects of organic nutrient management on aromatic rice (Oryza sativa)-linseed (Linum usitatissimum) sequence

The experiment was conducted during 2019 and 2020 at the Instructional-cum Research (ICR) Farm, Assam Agricultural University, Jorhat, Assam to study the impact of different combinations of organic nutrient sources on aromatic rice (Oryza sativa L.) (rainy-kharif) and their residual effect on linseed (Linum usitatissimum L.) (winter- rabi) crop for developing a double cropping sequence for rice growers of Assam with organic management. The experiment comprised three aromatic rice cultivars, viz. Kola joha, Keteki joha and Chakhao poireiton and five combinations of organic nutrient sources. Out of the organic nutrient sources, application of N @30 kg/ha through vermicompost along with pre-season green manuring of Sesbania bispinosa and root dip treatment of rice seedlings with Azospirillium and phosphorus solubilising bacteria @3.5 kg/ha each (N3) resulted the highest number of panicles/ m2 (216.72 in 2019 and 223.96 in 2020), highest yield of rice (30.26 q/ha in 2019, 32.58 q/ha in 2020 grain yield and 65.99 q/ha in 2019, 68.98 q/ha in 2020 straw yield). The highest seed yield (394.52 kg/ha in 2019, 416.97 kg/ha in 2020) and stover yield (890.09 kg/ha in 2019, 896.63 kg/ha in 2020) of succeeding relay sown linseed were recorded with the N3 treatment. The highest available N (250.10 kg/ha), P2O5 (20.40 kg/ha) and K2O (140.06 kg/ha), organic C (0.65%), soil organic carbon (SOC) stock (13.29 t/ha), soil microbial biomass carbon (SMBC) (183.43 µg/g of soil) in soil were recorded with the N3 treatment after harvest of linseed in 2020. The study affirmed the suitability of rice-linseed cropping sequence for efficient utilization and conservation of resources.

Optimization of the morphological, structural, and physicochemical properties of maize starch using straw returning and nitrogen fertilization in Northeast China

The combination of straw returning and nitrogen (N) fertilization is a popular tillage mode and essential strategy for achieving stable yield and high quality. However, the optimal combination strategy and the influence of tillage mode on the morphological, crystalline, and molecular structures of maize starch remain unclear. We conducted a long–term field experiment over 7 years in Northeast China using two tillage modes, rotary tillage with straw returning (RTS) and plow tillage with straw returning (PTS), and four N application rates. The relative crystallinity, 1045/1022 cm−1 value, and B2 and B3 chains of maize starch were higher under RTS than under PTS, resulting in increased stability of starch and improvements in gelatinization enthalpy and temperature. The surface of the starch granules induced by N fertilizer was smoother than that under the N0 (0 kg N ha−1) treatment. The proportion of amylose content, solubility, swelling power, and light transmittance increased under N2 (262 kg N ha−1) treatment, along with improvement in starch pasting properties. These results suggest that RTS combined with N2 treatment can regulate the morphological, structural, and physicochemical characteristics of maize starch, providing an essential reference for improving the quality of maize starch from an agronomic point of view.

Nitrogen mitigates the negative effects of combined heat and drought stress on winter wheat by improving physiological characteristics.

Extreme drought stress is often accompanied by heat stress after anthesis in winter wheat. Whether nitrogen (N) can mitigate the damage caused by combined stress on wheat plants by regulating root physiological characteristics is still unclear. Thus, this study aimed to study the effects of combined heat and drought stress on photosynthesis, leaf water relations, root antioxidant system, osmoregulatory, and yield in wheat to reveal the physiological mechanism of N regulating the adverse impacts of combined stress on wheat. Heat and drought stress markedly reduced photosynthesis, leaf water content, root vitality, and bleeding sap. The combination of heat and drought strengthens these changes. Within a certain stress range, the increase in soluble sugar and proline contents and the activities of superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase under combined stress effectively alleviated the oxidative damage. Compared with those under high N application (N3), wheat plants under low N application (N1) maintained higher yield and yield components under combined stress; the number of grains per spike, 1000-grain weight, and yield increased by 13.65%, 9.07%, and 15.33%, respectively, under N1 compared with those under N3 treatment, which may be attributed to the greater maintenance of photosynthesis, leaf water status, root vitality, and antioxidant and osmoregulation capacities. In summary, reduced N application mitigated the damage caused by combined heat and drought stress in wheat by improving root physiological characteristics and enhanced adaptability to combined stress, which is an appropriate strategy to compensate for yield losses.

Combined Application of Nitrogen and Phosphorus Promotes the Growth and Nutrient Accumulations of Cinnamomum camphora Container Seedlings

Combining the application of nitrogen and phosphorus is widely recognized as an effective measure to promote seedling growth. The purpose of this study was to investigate the effects of the combined application of nitrogen and phosphorus on the growth and nutrient status of C. camphora container seedlings. Exponential fertilization was applied to a range of fertilizers, including single nitrogen fertilizer, single phosphorus fertilizer, and combinations of nitrogen and phosphorus to C. camphora. Eight distinct fertilization levels of treatment (CK, N1, N2, N3, P, N1P, N2P, and N3P) were established. The height and ground diameter of the seedlings were determined periodically in each treatment group. Biomass, root system (including root length, root surface area, and root volume), and nutrient accumulation (content of soluble sugars, soluble proteins, and starch in the root system, stems, and leaves) were determined for each treatment group of seedlings. The N3P treatment (N: 9000 mg∙plant−1 + P: 6000 mg∙plant−1) had the most significant effect on the height and ground diameter of C. camphora container seedlings, while the N3 treatment (N: 9000 mg∙plant−1) proved to be the most beneficial for biomass accumulation among the eight different fertilizer levels. In addition, a single P fertilizer (P: 6000 mg∙plant−1) emerged as the most effective fertilizer for enhancing root morphology (root length, root surface area, root volume, and root average diameter) and accumulating nutrient composition (soluble sugar, soluble protein, and starch). Furthermore, it was discovered that a high level of nitrogen fertilization hindered the accumulation of nutrient composition in C. camphora container seedlings. Our comprehensive analysis revealed that nitrogen fertilizer promoted the morphological growth of C. camphora container seedlings, while phosphorus fertilizer proved to be the most beneficial for root growth and nutrient composition accumulation. Additionally, it was emphasized that controlling the quantity of nitrogen fertilizer is also a crucial measure.

Response of Mustard (Brassica juncea L.) to Different Bio-Regulators under Varying Fertility Levels

A field experiment on “Response of mustard (Brassica juncea L.) to different bio-regulators under varying fertility levels” was carried out at Agronomy Instructional Farm, Chimanbhai Patel College of Agriculture, S. D. Agricultural University, Sardarkrushinagar during rabi 2017-18. With regard to the effect of different bio-regulators on mustard, all growth attributes studied during the course of investigation such as dry matter accumulation per plant, number of primary branches and secondary branches per plant showed significant improvement due to application of cycocel (CCC) @ 1500 ppm (B3). Whereas significantly the lowest plant height was exhibited under treatment B3. Similarly, treatments B3 (Cycocel @ 1500 ppm) and B1 (Brassinosteroid @ 0.5 ppm) remained comparable and exhibited significantly higher values of yield components and quality parameters viz., number of seeds per siliqua, number of siliquae per plant, test weight, seed yield per plant, protein content and oil yield. Application of cycocel @ 1500 ppm (B3) also significantly increased N and S content in seed and stover and also resulted in significant improvement in uptake of N, P, S and Zn in seed, stover and total uptake followed by treatment B1 (Brassinosteroid @ 0.5 ppm). However, harvest index, phosphorus and zinc content in seed and stover as well as available nutrients status in the soil (N, P2O5, S and Zn) did not influenced due to application of different bio-regulators. Treatment B3 (Cycocel @ 1500 ppm) realized the highest net return (₹ 64,090/ha) followed by treatment B1 (Brassinosteroid @ 0.5 ppm). The results of the present investigation indicated that all the growth attributes in terms of plant height, number of primary and secondary branches per plant; yield attributes viz., number of seeds per siliqua, number of siliquae per plant, test weight, seed yield per plant, seed, stover yield and quality parameters viz., oil content, oil yield and protein content showed significant improvement due to application of balanced fertilization treatment N4 (N50P50S40Zn1.7), though it was at par with treatment N3 (N50P50S40). Application of N50P50S40Zn1.7 (N4) registered significantly higher N, P2O5, S and Zn content (%) in seed and stover and seed, stover and total uptake by mustard followed by treatment N3 (N50P50S40). Similarly, application of N50P50S40Zn1.7 (N4) noted significantly higher available N (180.38 kg/ha), P2O5(39.68 kg/ha), S (8.49 mg/kg) and Zn (0.46 mg/kg), being at par with treatment N3 (N50P50S40) except available Zn status in soil. From economic point of view, the maximum net return (₹ 64,897/ha) and benefit cost ratio (3.13) were received with application of 50 kg N + 50 kg P2O5+ 40 kg S + 1.7 kg Zn/ha (N4) followed by treatment N3 (N50P50S40).

PENGARUH PEMBERIAN PUPUK KANDANG AYAM DAN PUPUK NPK 17:17:17 TERHADAP PERTUMBUHAN BIBIT TANAMAN PORANG (Amorphophallus oncophyllus)

This study aims to determine the effect of giving chicken manure and NPK 17:17:17 fertilizer to the growth of Porang seedlings, as well as the interaction between the two. This study used a Randomized Block Design (RAK) with 2 factorials, namely, treatment of chicken manure (K) doses with 3 levels, namely: K1 = 20 gr/polybag, K2 = 40 gr/polybag and K3 = 60 gr/polybag, and treatment dose of NPK 17:17:17 (N) fertilizer with 3 levels, namely: N1 = 5 gr/polybag, N2 = 6 gr/polybag and N3 = 7 gr/polybag. The parameters observed in this study were: plant height (cm), stem diameter (cm), leaf width (cm) and number of leaves (strands). The results showed that the application of chicken manure had a significant effect on the leaf width parameter (cm). The best results were obtained in the K2 treatment (40 g/polybag). The application of NPK 17:17:17 fertilizer had a very significant effect on plant height (cm), stem diameter (cm) and number of leaves (strands). The best results were obtained in the N1 treatment (5 g/polybag). There is no interaction between chicken manure and NPK fertilizer 17:17:17.

Symbiotic nitrogen fixation enhanced crop production and mitigated nitrous oxide emissions from paddy crops

Feeding a growing population and preventing dangerous climate change are two challenges facing humanity. Biological nitrogen (N) fixation is considered a sustainable production measure that helps maintain crop production and mitigate climate change by supplementing alternative N nutrients. However, the simultaneous impacts of symbiotic N fixation (SNF) by leguminous green manure crops on rice crop production and nitrous oxide (N2O) emissions remain poorly understood. Here, a field experiment of two annual rotation cycles was conducted to monitor rice yield and the N2O emissions under rice (Oryza sativa subsp. japonica Kato.)-wheat (Triticum aestivum L.) (RW) and rice-hairy vetch (Vicia villosa Roth.) (RV) cropping systems at three N input rates (0 (N0), 50 (N1) and 100 (N2) kg ha−1) for the upland crops and 200 kg ha−1 for the rice crop. Growing hairy vetch introduced a significant amount of N as SNF to the agroecosystem, ranging from 123 to 182 kg ha−1. Compared to the treatments without N for the RV system, the N1 and N2 treatments significantly increased the amount of SNF by 44–47% and 19%− 24%, respectively. The cumulative N2O emissions from SNF ranged from 0.28–0.65 kg ha−1, with the N2O emission factor from SNF (EFSNF) ranging from 0.18%− 0.52% for the RV system. The RV system significantly decreased the N2O emission factor from the total N input (EFTN) by an average of 10.0% compared with the RW system. The RV-N1 treatment produced an obviously lower EFTN, averaging 0.37%, than the other treatments receiving N applications. Compared to the RW system, the RV system slightly increased rice yield by an average of 3.5%. Therefore, the most appropriate N application rate was 50 kg ha−1 for the leguminous crop, and SNF of leguminous green manure could serve as complementary to mineral N fertilizers for reducing N2O emissions while improving soil quality and rice yield in paddy field.

Analyzing the Impact of Simulated Nitrogen Deposition on Stoichiometric Properties and Yield of Ma Bamboo (Dendrocalamus latiflorus Munro) Shoots, Leaves, and Soil Substrate

The growth dynamics of Ma bamboo (Dendrocalamus latiflorus Munro) are intricately linked to nitrogen availability, a pivotal nutrient. Escalating global nitrogen deposition, primarily driven by anthropogenic factors, is reshaping nutrient fluxes and productivity within forest and bamboo ecosystems. Such alterations bear significant implications for the growth equilibrium and yields of rapid-growth species such as Ma bamboo, thereby influencing their sustainable management strategies. This investigation delves into the responses of Ma bamboo under varying nitrogen deposition scenarios (0 g·clump−1, 11.2 g·clump−1, 13.5 g·clump−1, and 22.5 g·clump−1), examining stoichiometric attributes in bamboo shoots, leaves, and soil across distinct growth phases. Our empirical findings reveal that in the early growth stage, nitrogen enrichment markedly augmented N and P concentrations in the foliage and shoots, alongside a corresponding enhancement in soil P content. This was paralleled by a substantial reduction in the C:N ratio in leaves and the C:P ratio in shoots and soil, indicating an amplified uptake of P and N in both plant and soil matrices. During the middle stage, all nitrogen treatments boosted nitrogen levels across various plant tissues, while concurrently, soil C content exhibited a notable decline with increased nitrogen supplementation. In the late stage, leaf and soil N content continued to ascend; however, alterations in C content in both soil and leaves were not pronounced. Contrastingly, N and P levels in shoots showed a gradual decrement. Yield assessments disclosed that during the early stage, the N3 treatment (22.5 g·clump−1) not only delayed shoot emergence by 14 days but also surged the yield by 115.87% in comparison to the control (CK). In the late stage, the N2 treatment (13.5 g·clump−1) extended emergence duration by 10 days, with the yield apex under N3 treatment (22.5 g·clump−1) evidencing a 116.67% yield augmentation over CK. In summation, this study elucidates the stoichiometric balancing and distribution strategies within the plant–soil system of Ma bamboo, investigating its adaptability and responsive feedback to diverse nitrogen deposition gradients. This research contributes to a deeper understanding of plant nutrient adaptation mechanisms in the context of nitrogen deposition, enriches the discourse on plant population stoichiometry, and offers valuable insights and scientific underpinnings for broader-scale community or ecosystem stoichiometry studies.

Nitrogen rate and harvesting time based on growing degree days influenced winter cereal rye morphological traits, forage yield, quality, and farm profit in poorly drained Alfisols

AbstractWinter cereal rye (Secale cereale L.) (WCR) is often double cropped with maize for silage (Zea mays L.) to increase farm forage supply and profit. Spring nitrogen (N) fertilization to WCR could influence its production and quality at different harvesting times. Therefore, two on‐farm trials were conducted in the 2019–2020 and 2020–2021 growing seasons to evaluate the effect of harvesting time (late‐March to end‐of‐April considering the growth stage) and spring N fertilization (0, 23, 47, and 71 kg N ha−1) on WCR morphology, forage yield, nutrient removal, quality, and farm profit. Only two N treatments (0 and 47 kg N ha−1) were evaluated for each harvesting time in trial 1. A quadratic model best explained an increase in WCR dry matter (DM) yield in response to growing degree days (GDD) accumulation (R2 = 0.81). An increase in GDD linearly decreased WCR relative forage quality (RFQ). Benchmarking RFQ at 150 for dairy milk production indicates WCR should be harvested at a GDD of 543, at which WCR plant height was 31.8 cm and DM yield was 0.77 Mg ha−1. This resulted in loss of profit in both study years compared to later harvesting dates at higher GDDs. Benchmarking RFQ at 125 for heifer production indicated that harvest should occur at a GDD of 668, at which the WCR was 71 cm tall, and its DM yield was 2.25 Mg ha−1. Nitrogen balances were negative at the N0 treatment (0 kg N ha−1), indicating a need for some N to maximize WCR yield. We found that a rate between 21 and 47 kg N ha−1 maximizes yields reflecting slightly positive balances, in which the highest profits occur. Our results suggest that the harvesting time can be predicted by GDD and should be adjusted for RFQ. We conclude that less than 47 kg N ha−1 N fertilizer is required for WCR production in soils with manure history and high soil organic matter (&gt;30 g kg−1).

Nitrogen fertilizer application rate affects the dynamic metabolism of nitrogen and carbohydrates in kernels of waxy maize.

Nitrogen (N) plays a pivotal role in the growth, development, and yield of maize. An optimal N application rate is crucial for enhancing N and carbohydrate (C) accumulation in waxy maize grains, which in turn synergistically improves grain weight. A 2-year field experiment was conducted to evaluate the impact of different N application rates on two waxy maize varieties, Jinnuo20 (JN20) and Jindannuo41 (JDN41), during various grain filling stages. The applied N rates were 0 (N0), 120 (N1), 240 (N2), and 360 (N3) kg N ha-1. The study revealed that N application significantly influenced nitrogen accumulation, protein components (gliadin, albumin, globulin, and glutelin), carbohydrate contents (soluble sugars, amylose, and amylopectin), and activities of enzymes related to N and C metabolism in waxy maize grains. Notable varietal differences in these parameters were observed. In both varieties, the N2 treatment consistently resulted in the highest values for almost all measured traits compared to the other N treatments. Specifically, the N2 treatment yielded an average increase in grain dry matter of 21.78% for JN20 and 17.11% for JDN41 compared to N0. The application of N positively influenced the activities of enzymes involved in C and N metabolism, enhancing the biosynthesis of grain protein, amylose, and amylopectin while decreasing the accumulation of soluble sugars. This modulation of the C/N ratio in the grains directly contributed to an increase in grain dry weight. Collectively, our findings underscore the critical role of N in regulating kernel N and C metabolism, thereby influencing dry matter accumulation in waxy maize grains during the grain filling stage.

Effects of nitrogen topdressing fertilization on yield and quality in soybeans

&lt;p&gt;Soybean [&lt;italic&gt;Glycine max&lt;/italic&gt; (L.)] has higher nitrogen requirements than other crops. We investigated the effects on soybean yield and quality of topdressing with nitrogen fertilizer. Nitrogen fertilizer was applied as a topdressing to soybeans at 0, 20, 30, and 40 kg ha&lt;sup&gt;−1&lt;/sup&gt; (N0, N20, N30, and N40 treatments, respectively); half of the total topdressing treatment was applied at the pre-flowering (R 1) stage and the other half at the post-flowering (R 2) stage. Yield was highest in the N20 treatment and decreased with larger quantities of topdressing. The protein and total amino acid content were highest in the N20 treatment but tended to decrease with a greater quantity of topdressing. contents of most individual amino acids peaked in the N20 or N30 treatments and decreased as topdressing quantity increased, although proline and arginine contents increased with quantity of topdressing. Isoflavone content tended to be highest in either the N30 or N20 treatment. The agronomic efficiency of nitrogen (AE&lt;sub&gt;N&lt;/sub&gt;) was highest in the N20 treatment. There was a positive correlation between AE&lt;sub&gt;N&lt;/sub&gt; and yield, protein, isoflavone, and amino acid content. Topdressing with 20 kg ha&lt;sup&gt;−1&lt;/sup&gt; N produced the highest yield, protein, and amino acid content. Topdressing with greater quantities of nitrogen fertilizer decreased the yield and quality of soybeans.&lt;/p&gt;