Physiological Nitrogen Efficiency Research Articles

Effect of nitrogen and boron treatments on harvest index and nitrogen use efficiency in sugar beet

The aim of this study is to examine the effect of different doses of nitrogen (N) and boron (B) treatment on sugar harvest index (SHI), nitrogen harvest index (NHI), and nitrogen use efficiency (NUE) parameters and to determine the economic optimum nitrogen rates (EONR) in sugar beet. The experiment was set up in a randomized block factorial design with three replications. Five doses of N (0, 90, 180, 270, and 360 kg N ha-1) and four doses of B (0, 2, 4, and 6 kg B ha-1) were applied in the study. According to the results of the research, the SHI decreased statistically significantly with the increase of dose of the N treatment, but the NHI was not affected by the N treatment. Physiological efficiency of nitrogen in taproot dry matter yield (NPETDMY) and physiological efficiency of nitrogen in sugar yield (NPESY) decreased statistically significantly (p<0.01) with the increase in the dose of N treatment. A similar case was observed in the parameters of nitrogen agronomic efficiency (NAgE) and nitrogen uptake efficiency (NUpE). The increase in boron treatment doses statistically significantly (p<0.01) increased the NAgE in the first year. The EONR, calculated using the quadratic model, was found to be 240 kg N ha-1 on average of two years. As a result, the nitrogen use potential decreased with the increase of N doses applied to sugar beet. The use of EONR can be recommended for optimum yield and quality in the region.

How Does Crop Rotation Influence Soil Moisture, Mineral Nitrogen, and Nitrogen Use Efficiency?

Rice–wheat (RW) cropping systems are integral to global food security. Despite being practiced for decades, Chinese RW cropping systems often suffer from low productivity and poor nitrogen use efficiency (NUE), reflecting management approaches that are not well-contextualized to region and season. Here, we develop the best management guides for N fertilizer in RW systems that are designed to help raise the productivity, NUE, and environmental sustainability of winter wheat over the long term. 2-year field experiments were conducted with four N fertilizer rates (0, 135, 180, and 225 kg N ha–1), allowing contrasts of yields, soil moisture, and NUE of wheat in RW in the humid climates zones on the Jianghan Plain. We compared RW systems with soybean/maize dryland wheat (DW) systems that are similarly endemic to China: after soybean/maize is harvested, soils are often drier compared with moisture content following rice harvest. With high seasonal N application rates (180–225 kg N ha–1), wheat crop yields increased by 24% in RW which were greater than comparable yields of wheat in DW, mainly due to greater kernels per spike in the former. Across treatments and years, N accumulation in plant tissue and kernel dry matter of DW was higher than that in RW, although mean agronomic efficiency of nitrogen (AEN) and physiological efficiency of nitrogen (PEN) of RW systems were greater. As N application rates increased from 135 to 225 kg ha–1, AEN and PEN of DW decreased but changed little for RW. Soil ammonium N was much lower than that of nitrate N; changes in NH4+ and NO3– as a consequence of increasing N fertilization were similar for RW and DW. We recommend that tactical application of N fertilizer continue seasonally until midgrain filling for both the DW and RW systems. At fertilization rates above 180 kg N ha–1, yield responses disappeared but nitrate leaching increased significantly, suggesting declining environmental sustainability above this N ceiling threshold. Collectively, this study elicits many functional and agronomic trade-offs between yields, NUE, and environmental sustainability as a function of N fertilization. Our results show that yield and NUE responses measured as part of crop rotations are both more robust and more variable when derived over multiple seasons, management conditions, and sites.

Nitrogen Recoveries and Nitrogen Use Efficiencies of Organic Fertilizers with Different C/N Ratios in Maize Cultivation with Low-Fertile Soil by 15N Method

The rising cost of inorganic fertilizers, coupled with their adverse effects on soil conditions, has resulted in increasing interest in organic amendments. The objective of the present study was to evaluate the effect of organic amendments (OAs) with different C/N ratios on nitrogen use efficiency (NUE) and recovery rate, as well as on the growth and yield of Zea mays and soil properties. A precise pot experiment was conducted on a low-fertile, sandy-loam soil, and the dynamics of nitrogen (N) were also analyzed by the A-value method, using 15N tracer. The plant height of the treatment groups decreased in the following order: inorganic fertilizer (IF) = rapeseed waste (RW) > chicken manure (CnM) > bamboo tealeaf (BTL) > cow manure (CwM) > bamboo compost (BC). Furthermore, the maize fertilized with RW only took up half of the N in IF, despite producing the same yield, which indicates that the physiological nitrogen efficiency (PUE) of RW was twice as high as that of IF. RW and CnM were regarded as valuable fertilizers that could be used to replace inorganic fertilizers. A linear relationship between the N mineralization of the OAs was obtained by an incubation test and the pot experiments, estimating the effect of OA application on the maize. Maize plants mainly absorbed N derived from fertilizers; however, for the both sources of N (fertilizer and soil), N was mainly accumulated in grains followed by the leaves, stem, and root, suggesting that studies should be conducted to improve soil N use efficiency.

Nitrogen Application Improved Photosynthetic Productivity, Chlorophyll Fluorescence, Yield and Yield Components of Two Oat Genotypes under Saline Conditions

: Understanding the interaction between salinity and nitrogen (N) nutrition is of great economic importance to improve plant growth and grain yield for oat plants. The objective of this study was to investigate whether N application could alleviate the negative effect of salinity (NaCl) stress on oat physiological parameters and yield performance. Two oat genotypes with contrasting salt tolerance response (6-SA120097, a salt-tolerant genotype SA and 153-ND121147, salt-sensitive ND) were grown under four N rates (0, 100, 200, and 400 mg N pot−1) in non-saline and saline (100 mM NaCl) conditions. The results showed that salinity, N fertilization and their interaction significantly affected the photosynthetic rate, transpiration rate, agronomic nitrogen use efficiency (aNUE), physiological nitrogen efficiency (pNUE) and apparent nitrogen recovery (ANR), seed number, and grain yield. Saline stress reduced gas exchange rate, nitrogen use efficiency (NUE), grain yield, and yield components. N fertilization increased photosynthetic productivity and chlorophyll fluorescence, resulting in improved grain yields and yield components for both genotypes. On average, the photosynthetic rate was increased by 38.7%, 74.1%, and 98.8% for SA and by 49.8%, 77.6%, and 110% for ND, respectively, under the N rates of 100, 200, and 400 mg N pot−1, as compared with non-fertilized treatment. In addition, grain yield was increased by 80.6% for genotype SA and 88.7% for genotype ND under higher N application rate (200 mg N pot−1) in comparison with the non-nitrogen treatment. Our experimental results showed that an increase of N supply can alleviate the negative effects induced by salinity stress and improved plant growth and yield by maintaining the integrity of the photosynthesis and chlorophyll fluorescence processes of oat plants, which provides a valuable agronomic strategy for improving oat production in salt-affected soils.

Mogućnosti korišćenja fiziološke efikasnosti azota u oplemenjivanju pšenice u smislu ekološke poljoprivrede

Inadequate amounts of fertilizers, especially nitrogen, have negative effects on ecosystems and food safety. On the other side, fertilizing, with an improvement in cropping systems, mainly in developed countries, has provided a food supply sufficient for both animal and human consumption. Therefore, with the increasing world population, the main task for the following decades is to develop highly productive agriculture, whilst at the same time preserving the quality of the environment. A multidisciplinary approach to winter wheat breeding and the inclusion of physiological indicators of nitrogen nutrition efficiency in this process could be helpful in reaching this goal. This study deals with the physiological efficiency of nitrogen as one of the physiological indicators, its relation with grain yield, heritability and variance and evaluation of Serbian winter wheat genotypes according to this indicator. The highest values of the physiological efficiency of nitrogen were registered at KG 165/2 and Lazarica. These genotypes, selected as superior in terms of this indicator, could be considered as desirable in wheat breeding theory, for improvement of production efficiency, environmental protection and development of ecological agriculture. However, further investigations of other physiological parameters, their correlations and correlations with yield and grain quality of wheat are necessary to define breeding programs and to obtain reliable results in this area.

Production potential of baby corn (Zea mays) on raised bed in waterlogged lowland rice fallow in North East India

A field experiment was conducted during rainy (Kharif) season of 2008-09 and 2009-10 at research farm of ICAR-Research Complex of NEH Region of Umiam, Meghalaya, to study the production potential of baby corn (Zea mays L.) as influenced by raised bed height in waterlogged low land area and nitrogen levels. Taller plants with more number of leaves were recorded with 50 cm height of raised bed. The days to harvest initiation and harvest duration were more at 50 cm height of raised bed. The barrenness in baby corn was also comparatively lesser with 50 cm height of raised bed. The maximum baby corn and fodder yield was recorded with 50 cm height of raised bed, which were 11.3 and 10.7% higher than 40 cm height of raised bed. Further, decrease in height of raised bed up to 30 and 20 cm markedly reduced babycorn yield as compared to 50 cm height of raised bed. The nitrogen content and uptake, protein yield, nitrogen use efficiency and economical parameters were also higher at 50 cm height of raised bed. Increasing nitrogen level produced taller plants with more number of leaves. The harvest initiation decreased by 4 days while harvest duration was increased by 4 days with 120 kg N/ha. The barrenness declined with increasing nitrogen levels. The highest baby corn yield, nitrogen uptake and protein yield were recorded with 80 kg N/ha. Increasing nitrogen levels progressively reduced agronomic N use efficiency and physiological efficiency of nitrogen, but apparent recovery increased up to 80 kg N/ha. The gross, net return and benefit: cost ratio were higher with 80 kg N/ha. Therefore, for getting higher yield and net return, the baby corn should be grown at 50 cm height above the moisture level on raised bed and fertilized at the rate of 80 kg N/ha.

Nitrogen agronomic efficiency of wheat in different crop rotations, and the application rates of nitrogen

This research was carried out under the temperate climate condition of Ilam province, Iran, during 2011-2013 growing seasons to determine the suitable crop rotation for enhancing the nitrogen use efficiency of wheat. The experiment was performed in a split plot arrangement based on randomized complete block design with 4 replications. The main plots consisted of 6 pre-sowing plant treatments (control, PerkoPVH, Buko, Clover, Oilseed radish and combination of three plants; Ramtil, Phasilia, and clover), and sub-plots were allocated to four levels of nitrogen fertilizer (Zero, fertilizer recommendation based on soil test, 50% lower and 50% higher than the recommended fertilizer).The results showed that there were significant differences among the presowing treatments for the grain yield. The highest and lowest grain yield, were obtained for Buko: wheat rotation and fallow: wheat rotation with 8345, and 4491 kg/ha, respectively. The highest and the lowest nitrogen uptake were obtained for Buko: wheat and clover: wheat rotation, respectively. The difference between the various rotations was significant for nitrogen agronomic efficiency. The rotation of oilseed radish: wheat increased nitrogen economic performance up to 20.36 kg/ha.The physiological nitrogen efficiency in fallow: wheat rotation was the highest with 39 kg kg-1 of nitrogen. The maximum nitrogen recovery efficiency were obtained for oilseed radish: wheat and PerkoPVH: wheat rotation with 45% and 36%, respectively.The highest nitrogen harvest index was observed in Buko: wheat rotation: (86.5%), and Perko: wheat (85%) and the lowest one in fallow: wheat (79.28%).

Interrelationship between grain yield and physiological parameters of winter wheat nitrogen nutrition efficiency

This paper deals with interrelationship between grain yield and some physiological parameters of wheat plant nitrogen nutrition efficiency as well as interrelationships between these parameters and some yield related traits (biological yield, grain harvest index). The aim of such investigation is to affirm possibilities of using physiological parameters of wheat plant nitrogen nutrition efficiency as criterions in breeding on its grain yield. The investigation, conducted as three years field trials, included 30 wheat cultivars and perspective lines. There were studied: nitrogen content in the above - ground part of plant at anthesis, in grain, in straw and total nitrogen content at maturity, nitrogen harvest index, nitrogen reutilization, post - anthesis nitrogen accumulation and physiological efficiency of nitrogen. The positive and statistically high significant relationships between nitrogen content in the above - ground part of plant at anthesis, in grain and in straw, total nitrogen content at maturity, nitrogen reutilization and post - anthesis accumulation as physiological parameters and grain yield were registered in investigated material. Most of listed parameters, important by grain yield aspect, can be studied easily and measured before wheat vegetative period ends. The investigated parameters can be recommended as criterions for selecting of parental pairs and evaluating progeny in breeding of wheat on grain yield, considering to their determined interrelationships and their measurability.

Effects of Different Plant Density and Nitrogen Application Rate on Nitrogen Use Efficiency of Potato Tuber

In order to investigate the plant density and nitrogen level on nitrogen use efficiency components (agronomical, physiological, apparent recovery and nitrogen use efficiency), the amount of nitrogen uptake by plant, yield and yield components of potato (Solanum tuberosum L.) Agria cultivars' tuber, a factorial experiment based on randomized complete block design was conducted in Ardabil, Iran, in 2006 with three replications. Factors were adjusted for the nitrogen level (0, 80, 160 and 200 kg ha(-1) net nitrogen) and plant density (5.5, 7.5 and 11 plant m(-2)). Results showed that with increasing the nitrogen levels and plant densities agronomical nitrogen use efficiency, physiological nitrogen efficiency and nitrogen use efficiency were decreased and apparent recovery nitrogen efficiency was increased. The most nitrogen uptake in plant was observed at the 200 kg ha(-1) net nitrogen. The most yield and number of tuber per unit area were gained at the 80 and 160 kg ha(-1) net nitrogen. Increasing the plant density resulted in increasing in the tuber yield per unit area and the rate of nitrogen up to the 160 kg ha(-1) net nitrogen. So, application of the 80 kg ha(-1) net nitrogen and plant density of 11 plant m(-2) is recommended to get highest yield with the most nitrogen use efficiency.

Nitrogen economy in old and modern malting barleys

Nitrogen (N) uptake at heading and at maturity was evaluated under four N treatments (20, 50, 110 and 160 kg N ha −1 at sowing) in four malting barley cultivars released to the market from 1944 to 1998 in Argentina. Grain N concentration was slightly lower in the newest cultivar than in the oldest one. Grain N yield showed cultivar × N interaction: modern cultivars tended to increase their grain N yield in response to N fertilization more than old cultivars. Grain N yield was correlated to grain yield as well as to total above-ground biomass. Nitrogen fertilization affected total N in above-ground biomass at maturity, but no differences among cultivars were found. Nitrogen harvest index of the most modern cultivar (0.76) was higher than that of the oldest cultivar (0.67). Modern cultivars tended to have a higher N content in ears at heading than old cultivars, and the magnitude of the differences increased with N availability. Physiological nitrogen efficiency for grain yield was significantly higher in the newest than in the oldest cultivar (57 and 43 g grain g N − 1 , respectively).

Soil fertility management in irrigated rice systems in the Sahel and Savanna regions of West Africa: Part I. Agronomic analysis

Yield, input use, productivity and profitability of irrigated rice systems were analyzed based on surveys in Senegal (Thiagar and Guédé), Mali (Office du Niger) and Burkina Faso (Kou Valley). The objective was to determine agronomic factors contributing to farmers' fertilizer-use efficiency and productivity, given current farmer practices. (A second paper addresses profitability and risk issues). Grain yields were highly variable, within and across sites. Minimum grain yield was 0.2 t ha −1 (Thiagar), maximum recorded grain yield was 8.7 t ha −1 (Office du Niger). The yield gap between actual farmers' yield and simulated potential or maximum attainable farmers' yield ranged from 0.6 to 5.7 t ha −1 (Kou), 1.8 to 8.2 t ha −1 (Thiagar), 0.3 to 6.3 t ha −1 (Office du Niger), 0.8 to 5.7 t ha −1 (Guédé), indicating considerable scope for improved yield. Physiological nitrogen efficiency (δ grain yield/δ N uptake) was mostly between 40 and 80 kg grain kg −1 plant N. Apparent recovery of fertilizer N was highly variable (average: 30–40% of applied N). Timing of N fertilizer application by farmers was extremely variable and often did not coincide with critical growth stages of the rice plant. Other agronomic constraints included: use of relatively old (>40 days) seedlings at transplanting (Kou, Office du Niger), P and/or K deficiency (Office du Niger), unreliable irrigation water supply (Kou, dry season), delayed start of the wet growing season resulting in yield losses of up to 20% due to cold-induced spikelet sterility (Kou, Guédé, Office du Niger), weed problems (Thiagar), and late harvesting (Thiagar). Discussions during meetings with farmers at the survey sites revealed that farmers lacked knowledge on (i) optimal timing, dosage and mode of fertilizer application, (ii) optimal sowing dates to avoid yield loss due to cold- or heat-induced sterility, and (iii) the importance of N as the main limiting factor to yield. Possibilities to achieve a sustainable increase in rice productivity and profitability in West African irrigation systems are discussed.

The agronomical and physiological efficiency of nitrogen applied for arable crops in Poland

The agronomical and physiological efficiency of nitrogen applied for arable crops in Poland

Apparent Recovery and Physiological Efficiency of Nitrogen in Sesbania Incorporated before Rice

AbstractWhen incorporated for lowland rice (Oryza sativa L.), the agronomic efficiency of green manure N exceeding 100 kg ha−1 is low. Apparent N recovery and physiological efficiency of green manure N, ranging to 200 kg N ha−1 were determined on a fine, mixed, isohyperthermic Aerie Tropaqualf in the Philippines. Sesbania sp. accumulated 100 kg N ha−1 in 48 d and 160 kg N ha−1 in 60 d. Nitrogen uptake (NU, kg N ha−1) from green manures flooded during the last 25 d before incorporation was a linear function of incorporated N (NU = 49 + 0.23N). Uptake from green manures that were not flooded diminished as incorporated N increased (NU = 35 + 0.51N – 0.0012N2). The flooding effect was attributed to inhibition of NO−3 accumulation on submerged control plots. Nitrogen uptake was linearly related to extractable NH+4‐N determined 7 d after green manure incorporation. As N uptake increased, however, physiological efficiency declined. Dry‐season rice recovered only 6% of the green manure N not recovered by wet‐season rice. Because both apparent recovery and physiological efficiency are low, and residual green manure N recovery is minor, the advantage to growing Sesbania sp. for more than 48 d to accumulate N in excess of 100 kg ha−1 is limited.