scholarly journals The Response of Grain Yield and Root Morphological and Physiological Traits to Nitrogen Levels in Paddy Rice

2021 ◽  
Vol 12 ◽  
Author(s):  
Wei Xin ◽  
Hualong Liu ◽  
Hongwei Zhao ◽  
Jingguo Wang ◽  
Hongliang Zheng ◽  
...  

Rice (Oryza sativa L.) is an important crop in China. Although it is known that its yield is restricted by nitrogen (N) supply, the response of the root system to N supply specifically has not been systematically explored. This study aimed to investigate the effect of N uptake on grain yield to clarify the relationships between root morphophysiological traits and N uptake, and to understand relation between phytohormones and root morphophysiological traits. Two N-efficient absorption cultivars (NEAs) and two N-inefficient absorption cultivars (NIAs) were grown in the field, and three N conditions, deficient N (60 kg ha–1), intermediate N (180 kg ha–1), and sufficient N (240 kg ha–1), were applied during the growing season. The results showed higher dry matter and grain yield in NEAs than in NIAs, which was mainly attributed to increased N uptake in the mid- and late growth stages under all N conditions. And NEAs have different root regulation methods to obtain higher N accumulation and yield under different N supply conditions. Under lower N conditions, compared with NIAs, NEAs shown greater total root length, root oxidation activity, and root active absorbing surface area and smaller root diameter owing to higher indole-3-acetic acid and cytokinin content and lower 1-aminocyclopropane-1-carboxylic acid content in the early growth stages to respond to low N stress faster, laying a morphophysiological basis for its high N-uptake capacity in the mid- and late growth stages. Under higher N conditions, NEAs had higher root oxidation activity and root active absorbing surface area for N uptake and yield formation owing to higher abscisic acid and cytokinin content in the mid- and late growth stages, which improved the seed setting rate, thereby increasing the rice grain yield. These results suggest that NEAs can optimize the morphophysiological characteristics of roots through phytohormone regulation to adapt to different nutrient conditions, thereby promoting N accumulation and yield formation in rice.

1999 ◽  
Vol 50 (2) ◽  
pp. 137 ◽  
Author(s):  
A. Kamoshita ◽  
M. Cooper ◽  
R. C. Muchow ◽  
S. Fukai

The differences in grain nitrogen (N) concentration among 3 sorghum (Sorghum bicolor (L.) Moench) hybrids with similar grain yield were examined under N-limiting conditions in relation to the availability of assimilate and N to grain. Several manipulation treatments [N fertiliser application, lower leaves shading, thinning (reduced plant population), whole canopy shading, canopy opening, spikelet removal] were imposed to alter the relative N and assimilate availability to grain under full irrigation supply. Grain N concentration increased by either increased grain N availability or yield reduction while maintaining N uptake. Grain N concentration, however, did not decrease in the treatments where relative abundance of N compared with assimilate was intended to be reduced. The minimum levels of grain N concentration differed from 0.95% (ATx623/RTx430) to 1.14% (DK55plus) in these treatments. Regardless of the extent of variation in assimilate and N supply to grain, the ranking of hybrids on grain N concentration was consistent across the manipulation treatments. For the 3 hybrids examined, higher grain N concentration was associated with higher N uptake during grain filling and, to a lesser extent, with higher N mobilisation. Hybrids with larger grain N accumulation had a larger number of grains. There was no tradeoff between grain N concentration and yield, suggesting that grain protein concentration can be improved without sacrificing yield potential.


2014 ◽  
Vol 153 (5) ◽  
pp. 862-875 ◽  
Author(s):  
J. BRENNAN ◽  
P. D. FORRISTAL ◽  
T. McCABE ◽  
R. HACKETT

SUMMARYField experiments were conducted between 2009 and 2011 in Ireland to compare the effects of soil tillage systems on the grain yield, nitrogen use efficiency (NUE) and nitrogen (N) uptake patterns of spring barley (Hordeum vulgare) in a cool Atlantic climate. The four tillage treatments comprised conventional tillage in spring (CT), reduced tillage in autumn (RT A), reduced tillage in spring (RT S) and reduced tillage in autumn and spring (RT A+S). Each tillage system was evaluated with five levels of fertilizer N (0, 75, 105, 135 and 165 kg N/ha). Grain yield varied between years but CT had a significantly higher mean yield over the three years than the RT systems. There was no significant difference between the three RT systems. Tillage system had no significant effect on the grain yield response to fertilizer N. As a result of the higher yields achieved, the CT system had a higher NUE than the RT systems at all N rates. There was no significant difference in NUE between the three RT systems. Conventional tillage had significantly higher nitrogen uptake efficiency (NUpE) than RT A and a significantly higher nitrogen utilization efficiency (NUtE) than all three RT systems. Crop N uptake followed a similar pattern each year. Large amounts of N were accumulated during the vegetative growth stages while N was lost after anthesis. Increased N rates had a positive effect on N uptake in the early growth stages but tended to promote N loss later in the season. The CT system had the highest N uptake in the initial growth stages but its rate of uptake diminished at a faster rate than the RT systems as the season progressed. Tillage system had an inconsistent effect on crop N content during the later growth stages. On the basis of these results it is concluded that the use of non-inversion tillage systems for spring barley establishment in a cool oceanic climate remains challenging and in certain conditions may result in a reduction in NUE and lower and more variable grain yields than conventional plough-based systems.


Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1752 ◽  
Author(s):  
Yingying Cheng ◽  
Yi Wang ◽  
Yanlai Han ◽  
Dongya Li ◽  
Zhongkui Zhang ◽  
...  

Nanochitin whisker (NC) with a cationic nature could enhance plant photosynthesis, grain yield, and quality of wheat, but have not been systematically studied. This study was designed to investigate the stimulatory effects of NC on dry matter (DM) and nitrogen (N) accumulation and translocation, and on the metabolism of carbon (C) and N in later growth stages of winter wheat to reveal the enhancement mechanism of grain yield and crude protein concentration. Different parts of NC-treated plants from pot grown experiments were collected at the pre- and post-anthesis stages. The accumulation, translocation, and contributions of DM and N from pre-anthesis vegetation organs to grains, as well as key metabolic enzyme activities, including sucrose phosphate synthase (SPS) and phosphoenolpyruvate carboxylase (PEPC), were examined. The results showed that, at an application rate of 6 mg·kg−1 of NC in the soil, the accumulation of DM and N were significantly enhanced by 16.2% and 38.8% in pre-anthesis, and by 15.4% and 30.0% in post-anthesis, respectively. Translocation of N and DM in the post-anthesis periods were enhanced by 38.4% and 50.9%, respectively. NC could also stimulate enzyme activities, and increased 39.8% and 57.1% in flag leaves, and by 36.0% and 58.8% in spikes, respectively, at anthesis. SPS and PEPC increased by 28.2% and 45.1% in flag leaves, and by 42.2% and 56.5% in spikes, respectively, at 15 days after anthesis. The results indicated that the NC promoted N metabolism more than C metabolism, and resulted in the enhancement of grain yield by 27.56% and of crude protein concentration in grain by 13.26%, respectively.


2020 ◽  
Author(s):  
Bharat Prakash Meena ◽  
Pramod Jha ◽  
K. Ramesh ◽  
A.K. Biswas ◽  
R. Elanchezhian ◽  
...  

AbstractConventionally, non-judicious and blanket fertilizer nitrogen (N) used in rainfed maize lead to higher N losses, low N use efficiency (NUEs) and poor yields due to substandard agronomic management practices. To avoid such N losses, fertilizer additions are synchronized with plant uptake requirements. In this context, agronomic based management focused on optimizing N rates and biochar application is essential for improved NUEs and crop productivity. Keeping this in view, a field experiment was conducted during 2014, 2015 and 2016 in rainfed maize (Zea mays L.) grown in Vertisols of India. In this study, twelve treatments that comprised of N omission plot (N0), skipping of basal rate, multi-split topdressing at varying time as broadcast and band placement, soil test crop response (STCR) based NPK with target yield 6.0 t ha-1 in maize and biochar application (10 t ha−1) were investigated. The experiment was conducted following a Randomized Complete Block Design (RCBD) set up with three replications. Pooled analysis of three years data revealed that the application of N rates (120 kg Nha−1) in 2 equal splits (60 kg Nha−1) at knee high (V8) and tasseling (VT) stages with skipped basal N rate, achieved higher maize grain yield (5.29 t ha−1) ascribed to the greater growth parameters, yield components and N uptake compared to the recommended practices. Biochar application (10 t ha−1) as soil amendments along with multi top dressed N (120 kg N ha−1) into 3 splits also increased the grain yield. Delayed N application at V8 and VT growth stages, resulted in higher N uptake, agronomy efficiency (AE), partial factor productivity (PFP), physiology efficiency (PE) and recovery efficiency (RE). Biochar along with N fertilizer also improved the soil organic carbon (5.47g kg−1), ammonium-N (2.40 mg kg−1) and nitrate-N (0.52 mg kg−1) concentration in soil (P<0.05) as compared to non-biochar treatments. Application of biochar along with chemical fertilizer (120 kg Nha−1) significantly increased the concentration of ammonium (2.40 mg kg−1) and nitrate (0.52 mg kg−1) in soil (P<0.05) as compared to non-biochar treatments. The perfect positive linear relationship illustrated that the grain yield of rainfed maize was highly dependent (R2=0.99 at p<0.0001) on N availability, as indicated by the fitted regression line of maize grain yield on N uptake. On the other hand, factor analysis revealed, the one to one positive function relationship of biomass with N uptake at V8 and VT growth stages. Principal Component Regression (PCR) analysis showed that PC1 acted as a major predictor variable for total dry matter yield (TDMY) and dominated by LAI and N uptake. Consequently, these results expressed that the agronomic management based multi-top dressed N application and biochar application to achieve higher yield and greater NUEs in rainfed maize is strongly linked with N application into splits.


1998 ◽  
Vol 49 (4) ◽  
pp. 695 ◽  
Author(s):  
S. Boonchoo ◽  
S. Fukai ◽  
Suzan E. Hetherington

Two types of experiments were conducted with the malting barley cv. Grimmett to examine how assimilate and nitrogen (N) availability at different growth stages determined yield and grain protein concentration (GPC) in south-east Queensland. In one series of experiments, plants were sown in April, June, and August so that they would experience different growing conditions, and responses to N application rate were examined. Another experiment examined response of growth, yield, and GPC to variation of assimilate production pre and post anthesis, caused by the canopy manipulation treatments of opening, closure, and 50% shading at 3 different growth stages. Without N application all 3 sowings produced similar yields (1·9-2·3 t/ha), but when N was applied, yield was higher and responded more to applied N in the June sowing than in the other sowings.The different responses of grain yield to N application rate among the 3 sowing dates were not due to differences in N uptake but to the efficiency of N use; with favourable temperatures throughout crop growth, the crop sown in June utilised N most eciently to develop a large number of grainsand to produce sufficient as similates to fill these grains. When yield had a positive response to low N application rates, then there was generally no response of GPC, whereas when there was no response of grain yield to further rate of N application then GPC increased. The results of the second experiment show that N uptake depended on plant N demand at early stages of growth when N was still available in the soil, but total N content of tops at maturity was similar among canopy manipulation treatments. Canopy opening at any stage of growth tended to increase tiller number, leaf area index, and above-ground dry matter, but the effect was greater attillering stage which produced the highest yield because of the greatest number of heads. Shading reduced yield at all stages, but particularly at pre-anthesis. Shading and canopy closure during grain filling reduced grain yield, but with similar N uptake these treatments significantly increased GPC .These results indicate that GPC depends on both assimilate and N availability to grain, and GPC can increase sharply when grain yield is reduced with low assimilate availability as a result of adverse growing conditions. Responses of grain yield to applied N depended on environmental conditions, particularly the patterns of air temperature during growth, and the crop utilised N more efficiently to produce higher yield when it was not exposed to extreme temperatures during the latter stages of growth.


Soil Research ◽  
2021 ◽  
Vol 59 (3) ◽  
pp. 318
Author(s):  
Pilar Muschietti Piana ◽  
Therese Marie McBeath ◽  
Ann Marie McNeill ◽  
Pablo Ariel Cipriotti ◽  
Vadakattu Gupta

In semiarid sandy soil environments there is a dual challenge of carbon and nitrogen (N) limitation that needs to be managed to ensure timely supply of N to crops. Management of N inputs to soil using combinations of legume stubble addition and fertiliser N in cereal systems is essential to meet crop demand and maintain N in soil organic matter. The aim of this study was to assess soil mineral and biological N pools that influence N supply and N uptake of wheat at early growth stages. The recovery of 15N-labelled fertiliser by wheat was evaluated using a factorial combination of either wheat, lupin or no stubble incorporated with or without 15N fertiliser in a sandy soil system. Soil and plant samples were collected at sowing, tillering, first node and booting to monitor changes in N pools and 15N uptake by the wheat. Crop stubble incorporation one week before sowing increased biological N pools in the surface soil (0–10 cm). Early N immobilisation (sowing–tillering) in all the treatments without 15N fertiliser may have limited N availability for wheat uptake in the subsequent period (tillering–first node), when fertiliser N appeared critical to maximise N supply for plant requirements. Up to 38% of the 15N fertiliser applied at sowing was incorporated into the soil microbial biomass pool, so that fertiliser N was critical to relieve short-term inherent N limitations for both plant and microbial growth, and to supply the longer-term biological pools (microbial biomass) to support subsequent mineralisation potential. Reducing the energy limitation to the microbial pool through inputs of carbon from stubble was also critical to ensure fertiliser N supplied sufficient N to satisfy plant demand later in the growing period. These results have implications for management decisions on semiarid sandy soil systems that aim to synchronise N from inputs of legume stubbles and fertiliser with crop N demand during early growth stages of wheat.


Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 171
Author(s):  
Tao Sun ◽  
Xin Yang ◽  
Xiaoli Tan ◽  
Kefeng Han ◽  
Sheng Tang ◽  
...  

Previous studies have revealed that the japonica/indica hybrid rice has a higher yield potential, biomass production, and nitrogen (N) accumulation than japonica rice in China, however, at a single N application rate. It remains unclear whether it also occurs at a higher or lower N application rate under the same field condition. To investigate the effects of nitrogen application rates on grain yield, N uptake, dry matter accumulation, and agronomic N use efficiency, field experiments were conducted in Jinhua City, Zhejiang Province during three consecutive growth seasons in 2016, 2017, and 2018. Two japonica/indica hybrid varieties (Yongyou 12 and Yongyou 538) and two japonica varieties (Xiushui 134 and Jia 58) were exposed to five N application rates (0, 150, 225, 300, and 375 kg ha−1). The results showed that grain yields of all the varieties increased with increasing nitrogen application rates, except for Jia 58 whose optimum nitrogen level was 225 kg ha−1, because no significant difference was observed between N225 and N300. Across the four rice varieties, N uptake increased significantly with increased N-fertilizer rates at all the growth stages (p < 0.05). Across the three planting years, the average grain yield of japonica/indica hybrid rice was higher than that of japonica rice by 75.6% at N0, 57.2% at N150, 41.1% at N225, 38.3% at N300, and 45.8% at N375. We also found that as compared with japonica rice, the japonica/indica hybrid rice had more grain yield, higher dry matter, and higher N uptake at all growth stages, regardless of the N application rate.


Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1183 ◽  
Author(s):  
Yangyang Zhang ◽  
Piaopiao Lu ◽  
Tao Ren ◽  
Jianwei Lu ◽  
Li Wang

Cultivation of winter oilseed rape hybrids has been introduced as a promising solution to improve the nitrogen use efficiency (NUE) and to reduce the large N balance surpluses in this crop. To achieve a better understanding of the underlying physiological mechanisms, field experiments were conducted over two years to investigate the dynamics of growth and N capture in an oilseed rape hybrid and its parental lines under both low (0 kg ha−1) and high (180 kg ha−1) N supply. The results showed that the dynamic trajectories of crop growth and N capture could be accurately characterized by logistic equation using growing degree days as the independent variable. At both N rates, the oilseed rape hybrid outperformed the parental lines in seed yield and aboveground biomass accumulation, which was more closely associated with the longer duration (td) of the rapid growth period (RGP), than with the higher maximum growth rate (vm). N uptake was the main factor driving genotypic variation in seed yield, with an increasing importance of N utilization efficiency at high N supply. The hybrid had significantly higher N uptake than the parental lines at both low and high N supply, because of larger vm for N accumulation during the RGP, which may present a scope for genetically improving NUE in oilseed rape. High N application enhanced crop biomass production and N accumulation, as a result of prolonged td and larger vm during the RGP. The initiation of RGP for N accumulation occurred after overwinter period, which could not be accelerated by high N supply, suggesting rational distribution of N fertilizer with reduced basal dose. However, larger amounts in spring would be beneficial for a better synchronization to crop N demand with lower environmental risks.


Soil Research ◽  
2016 ◽  
Vol 54 (5) ◽  
pp. 619 ◽  
Author(s):  
Robert H. Harris ◽  
Roger D. Armstrong ◽  
Ashley J. Wallace ◽  
Oxana N. Belyaeva

Some of the highest nitrous oxide (N2O) emissions arising from Australian agriculture have been recorded in the high-rainfall zone (>650mm) of south-western Victoria. Understanding the association between nitrogen (N) management, crop N uptake and gaseous losses is needed to reduce N2O losses. Field experiments studied the effect of N-fertiliser management on N2O emissions, crop N uptake and crop productivity at Hamilton and Tarrington in south-western Victoria. Management included five rates of urea-N fertiliser (0, 25, 50, 100 and 200kgN/ha) topdressed at either mid-tillering or first-node growth stages of wheat development; urea-N deep-banded 10cm below the seed at sowing; and urea coated with the nitrification inhibitor DMPP (3,4-dimethylpyrazole phosphate) was either topdressed or deep-banded. Pre-sowing soil profile chemical properties were determined before static chambers were installed to measure N2O losses, accompanied by wheat dry matter, crop N uptake and grain yield and quality, to measure treatment differences. N2O losses increased significantly (P≤0.10) where urea-N was deep-banded, resulting in a 2–2.5-fold increase in losses, compared with the nil N control. The high N2O losses from deep-banding N appeared to result from winter waterlogging triggering gaseous or drainage losses before wheat reached peak growth and demand for N in spring. Despite the high losses from deep-banding urea-N, grain yields were largely unaffected by N management, except at Hamilton in 2012, where topdressed wheat growing in a soil with large reserves of NO3–-N, and later experiencing post-anthesis water deficit resulted in a negative grain yield response. All sites had high concentrations of soil organic carbon (>2.8%) and the potential for large amounts of N mineralisation throughout the growing season to supplement low N fertiliser recovery. However, topdressed urea-N resulted in significant enrichment of crop tissue (P≤0.004) and associated positive response in grain protein compared with the deep banded and nil N treatments. 3,4-Dimethylpyrazole phosphate (DMPP)-coated urea provided no additional benefit to crop yield over conventional urea N. Our study highlighted the importance of synchronising N supply with peak crop N demand to encourage greater synthetic N uptake and mitigation of N2O losses.


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