YIELD OF POTATO CULTIVARS AS A FUNCTION OF NITROGEN RATES

ABSTRACT The use of fertilizers at appropriate doses positively impacts the production and the environment. Therefore, we aimed to evaluate the influence of nitrogen (N) rates on the crop yields of the potato cultivars, Ágata and Atlantic in Unaí, Minas Gerais (MG), and Ágata in Mucugê, Bahia (BA), Brazil. The cultivation of Ágata and Atlantic was conducted in MG from May to August and June to September 2014, respectively. In BA, Ágata was cultivated between September and December 2014. A random block experimental design was used with treatment rates of 0, 30, 70, 120, and 280 kg ha-1 of N. The macro and micronutrient concentrations in potato leaves were evaluated. At the end of the growth cycle, the production of tubers was also evaluated. In the absence of N application, it was observed that P, K, S, and B were below the adequate levels in Atlantic-MG, the S and Zn levels were lower than the adequate levels in Ágata -MG, and the N, K, Mg, and S levels were less than the adequate levels in Ágata-BA. The other nutrients met the needs of the potato, with the N increase being favorable to the levels of most nutrients in all experiments. The maximum rates of N varied between 138 and 194 kg ha-1 in the high and low cationic exchange capacity (CEC) regions, respectively. The knowledge of the interaction among soil attributes, climate conditions and crop specificities allows for the improved prediction of the dosage of N and a reduction in the optimum amount without affecting yields.

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Effect of Different Rates of Nitrogen Fertilization on Crop Yield, Soil Properties and Leaf Physiological Attributes in Banana Under Subtropical Regions of China

Frontiers in Plant Science ◽

10.3389/fpls.2020.613760 ◽

2020 ◽

Vol 11 ◽

Author(s):

Jianbo Sun ◽

Wenbin Li ◽

Chunqiang Li ◽

Wenjun Chang ◽

Shiqing Zhang ◽

...

Keyword(s):

Soil Properties ◽

Crop Yield ◽

Crop Yields ◽

Southern China ◽

N Fertilization ◽

Physiological Factors ◽

N Application ◽

Crop Physiology ◽

Physiological Attributes ◽

N Rates

Excessive nitrogen (N) application is widespread in Southern China. The effects of N fertilization on soil properties and crop physiology are poorly understood in tropical red loam soil. We conducted a field experiment to evaluate the effect of nitrogen fertilization rates on physiological attributes (chlorophyll, plant metabolic enzymes, soluble matters) on banana leaves, soil properties (soil enzymes, soil organic matter (SOM), soil available nutrients) as well as banana crop yield in a subtropical region of southern China. The N rates tested were 0 (N0), 145 (N145), 248 (N248), 352 (N352), 414 (NFT), and 455 (N455) g N per plant. The correlations among soil factors, leaf physiological factors and crop yield were evaluated. The results indiated that the high rates of N fertilization (NFT and N455) significantly decreased soil available potassium (K) content, available phosphorus (P) content, glutamine synthetase (GS) activity, and soluble protein and sugar contents compared with lower N rates. The N352 treatment had the highest crop yields compared with higher N rates treatments, followed by the N455 treatment. However, there were no significant differences in crop yields among N fertilization treatments. Factor analysis showed that the N352 treatment had the highest integrated score for soil and leaf physiological factors among all treatments. Moreover, the N352 treatment was the most effective in improving carbon and nitrogen metabolism in banana. Crop yield was significantly and positively linearly correlated with the integrated score (r = 0.823, p < 0.05). Path analysis revealed that invertase, SOM and sucrose synthase (SS) had a strong positive effect on banana yield. Canonical correspondence analysis (CCA) suggested that available K, invertase, acid phosphatase and available P were the most important factors impacting leaf physiological attributes. Cluster analysis demonstrated distinct differences in N application treatment related to variations in soil and leaf factors. This study suggested that excessive N fertilization had a negative effect on soil fertility, crop physiology and yield. The lower N rates were more effective in improving crop yield than higher rates of N fertilization. The N rate of 352 g N per plant (N352) was recommended to reduce excess N input while maintaining the higher yield for local farmers’ banana planting.

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Effects of various nitrogen regimes on the ability of rapeseed (Brassica napus L.) to suppress littleseed canarygrass (Phalaris minor Retz.)

10.21203/rs.3.rs-38850/v2 ◽

2021 ◽

Author(s):

Gaofeng Xu ◽

Shicai Shen ◽

Yun Zhang ◽

David Roy Clements ◽

Shaosong Yang ◽

...

Keyword(s):

Weed Control ◽

Competitive Ability ◽

Photosynthetic Characteristics ◽

Growth Stages ◽

Invasive Weeds ◽

Control Efficacy ◽

N Application ◽

Phalaris Minor ◽

N Rates ◽

Nitrogen Rates

Abstract Background: Littleseed canarygrass (Phalaris minor Retz.) is one of the most troublesome invasive weeds infesting winter crops in Yunnan Province, China. Our previous study found that rapeseed (Bassica napus L.) was a logical candidate crop to control littleseed canarygrass in agroecosystems. Nitrogen (N) could impact plant community composition by altering competitive interactions, however, the effects of different N regimes on weed control efficacy of rapeseed were unknown. Here, we report the effects of different N regimes on the competitiveness of rapeseed with littleseed canarygrass and accompanying differences in photosynthetic characteristics. Results: The results showed that the rapeseed yield and its control efficacy on littleseed canarygrass were significantly affected (P<0.05) under different N regimes, and the control efficacy of littleseed canarygrass by rapeseed increased first and then decreased with the increase of basal nitrogen rates, while increasing topdressing N rates increased control efficacy of littleseed canarygrass by rapeseed. In fact, yield and weed control efficacy of rapeseed was most ideal when both basal and top-dressing N was 90 kg·ha-1. We also found that N significantly impacted the competitive ability of rapeseed to littleseed canarygrass and rapeseed had the highest competitive ability when both basal and top-dressing N was 90 kg·ha-1. With the increase of basal nitrogen rates, competitive balance index (CB) of rapeseed increased initially but decreased beyond an optimal level. CB continually increased with increasing of topdressing N rates. Our research also showed level and period of N application had a significant effect (P<0.01) on the photosynthetic rate (Pn) and chlorophyll content (Chl) of both rapeseed and littleseed canarygrass. Under the same N application regime, the Pn and Chl of littleseed canarygrass were higher than that of rapeseed in December, while the Pn and Chl of rapeseed was higher than that of littleseed canarygrass in February. Our study indicated that photosynthetic characteristics of rapeseed and littleseed canarygrass in different growth stages differ in their sensitivity to N regimes, creating a dynamic competitive relationship. Conclusions: Together, our results demonstrated that optimal application of fertilizer N could help rapeseed produce higher yields and greater weed control efficacy, suggesting that future modeling or experimental studies on utilizing crops to control invasive weeds should carefully consider both timing and placement of N.

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INFLUENCE OF HARVEST SYSTEMS AND NITROGEN RATES ON YIELDS, QUALITY AND PERSISTENCE OF CHAMP TIMOTHY IN THE SEEDING AND POSTSEEDING YEARS

Canadian Journal of Plant Science ◽

10.4141/cjps76-112 ◽

1976 ◽

Vol 56 (3) ◽

pp. 715-723 ◽

Cited By ~ 8

Author(s):

H. T. KUNELIUS ◽

M. SUZUKI ◽

K. A. WINTER

Keyword(s):

Full Range ◽

Phleum Pratense ◽

In Vitro Digestibility ◽

N Application ◽

System A ◽

Yield Quality ◽

N Rates ◽

Nitrogen Rates ◽

Phleum Pratense L

The interaction effects of harvest systems and rates of N on yield, quality and persistence of Champ timothy (Phleum pratense L.) were studied in a 4-yr field experiment. In the seeding year, total dry matter (DM) yields were highest (4.41 tons/ha) for the harvest taken 12 wk after seeding. Total DM yields increased with increasing N application up to 148 kg N/ha/yr. During the 3 postseeding yr, timothy was harvested four (system A), three (B) or two (C) times per season. Nitrogen was applied at five rates from 33 to 165 kg/ha; three times for systems A and B and twice per season for system C. Total DM yields showed increases for the full range of N application for systems A and B, but up to 132 kg/ha/application for system C. The tissue N concentrations were increased by increasing rates of fertilizer N while the in vitro digestibility of DM (IVDDM) was not generally changed. Forage with high IVDDM of 68.0 to 72.0% was produced under systems A and B whereas under C, IVDDM ranged from 55.9 to 65.1% during the season. The NO3-N concentrations of tissue frequently exceeded 0.15% levels at N rates above 132 kg/ha/application. High rates of N tended to thin the stand, but weeds were most prevalent where the lowest N rate was used.

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Effects of various nitrogen regimes on the ability of rapeseed (Brassica napus L.) to suppress littleseed canarygrass (Phalaris minor Retz.)

10.21203/rs.3.rs-38850/v1 ◽

2020 ◽

Author(s):

Gaofeng Xu ◽

Shicai Shen ◽

Yun Zhang ◽

David Roy Clements ◽

Shaosong Yang ◽

...

Keyword(s):

Weed Control ◽

Competitive Ability ◽

Photosynthetic Characteristics ◽

Growth Stages ◽

Invasive Weeds ◽

Control Efficacy ◽

N Application ◽

Phalaris Minor ◽

N Rates ◽

Nitrogen Rates

Abstract Background: Littleseed canarygrass (Phalaris minor Retz.) is one of the most troublesome invasive weeds infesting winter crops in Yunnan Province, China. Our previous study found that rapeseed (Bassica napus L.) was a logical candidate crop to control littleseed canarygrass in agroecosystems. Nitrogen (N) could impact plant community composition by altering competitive interactions, however, the effects of different N regimes on weed control efficacy of rapeseed were unknown. Here, we report the effects of different N regimes on the control efficacy of littleseed canarygrass by rapeseed and their competitive effects and photosynthetic characteristics. Results: The results showed that the rapeseed yield and its control efficacy on littleseed canarygrass were significantly affected (P<0.05) under different N regimes, and the control efficacy of littleseed canarygrass by rapeseed increased first and then decreased with the increase of basal nitrogen rates, while increasing topdressing N rates increased control efficacy of littleseed canarygrass by rapeseed only. In fact, yield and weed control efficacy of rapeseed was most ideal when both basal and top-dressing N was 90 kg·ha-1. We also found that N significantly impacted the competitive ability of rapeseed to littleseed canarygrass and rapeseed had a highest competitive ability when both basal and top-dressing N was 90 kg·ha-1. With the increase of basal nitrogen rates, competitive balance index (CB) of rapeseed increased first and then decreased, but which gradually increased with increasing of topdressing N rates. Our research also showed level and period of N application had a significant effect (P<0.01) on the photosynthetic rate (Pn) and chlorophyll content (Chl) of both rapeseed and littleseed canarygrass. Under the same N application regime, the Pn and Chl of littleseed canarygrass were higher than that of rapeseed in December, while the Pn and Chl of rapeseed was higher than that of littleseed canarygrass in February. Our study indicated that photosynthetic characteristics of rapeseed and littleseed canarygrass in different growth stages differ in their sensitivity to N regimes, creating a dynamic competitive relationship. Conclusions: Together, our results demonstrated that rational application of fertilizer N could help rapeseed produce higher yields and greater weed control efficacy, suggesting that future modeling or experimental studies on utilizing crops to control invasive weeds should carefully consider both timing and placement of N.

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INFLUENCE OF THE SYSTEM OF RICE INTENSIFICATION ON RICE YIELD AND NITROGEN AND WATER USE EFFICIENCY WITH DIFFERENT N APPLICATION RATES

Experimental Agriculture ◽

10.1017/s0014479709007583 ◽

2009 ◽

Vol 45 (3) ◽

pp. 275-286 ◽

Cited By ~ 70

Author(s):

LIMEI ZHAO ◽

LIANGHUAN WU ◽

YONGSHAN LI ◽

XINGHUA LU ◽

DEFENG ZHU ◽

...

Keyword(s):

Water Use Efficiency ◽

Water Use ◽

N Use Efficiency ◽

System Of Rice Intensification ◽

N Application ◽

Application Rates ◽

Rice Intensification ◽

Use Efficiency ◽

N Rates ◽

N Use

SUMMARYField experiments were conducted in 2005 and 2006 to investigate the impacts of alternative rice cultivation systems on grain yield, water productivity, N uptake and N use efficiency (ANUE, agronomic N use efficiency; PFP, partial factor productivity of applied N). The trials compared the practices used with the system of rice intensification (SRI) and traditional flooding (TF). The effects of different N application rates (0, 80, 160 and 240 kg ha−1) and of N rates interacting with the cultivation system were also evaluated. Resulting grain yields with SRI ranged from 5.6 to 7.3 t ha−1, and from 4.1 to 6.4 t ha−1 under TF management. On average, grain yields under SRI were 21% higher in 2005 and 22% higher in 2006 than with TF. Compared with TF, SRI plots had higher harvest index across four fertilizer N rates in both years. However, there was no significance difference in above-ground biomass between two cultivation systems in either year. ANUE was increased significantly under SRI at 80 kg N ha−1 compared with TF, while at higher N application rates, ANUE with SRI was significantly lower than TF. Compared with TF, PFP under SRI was higher across all four N rates in both years, although the difference at 240 kg N ha−1 was not significant. As N rate increased, the ANUE and PFP under both SRI and TF significantly decreased. Reduction in irrigation water use with SRI was 40% in 2005 and 47% in 2006, and water use efficiency, both total and from irrigation, were significantly increased compared to TF. With both SRI and TF, the highest N application was associated with decreases in grain yield, N use efficiency and water use efficiency. This is an important finding given current debates whether N application rates in China are above the optimum, especially considering consequences for soil and water resources. Cultivation system, N rates and their interactions all produced significant differences in this study. Results confirmed that optimizing fertilizer N application rates under SRI is important to increase yield, N use efficiency and water use efficiency.

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Nitrogen fertiliser alleviates the disorder straighthead in Australian rice

Australian Journal of Experimental Agriculture ◽

10.1071/ea05004 ◽

2006 ◽

Vol 46 (8) ◽

pp. 1077 ◽

Cited By ~ 13

Author(s):

B. W. Dunn ◽

G. D. Batten ◽

T. S. Dunn ◽

R. Subasinghe ◽

R. L. Williams

Keyword(s):

Plant Growth ◽

Growth And Yield ◽

High Nitrogen ◽

Physiological Disorder ◽

N Application ◽

Nitrogen Fertiliser ◽

Eastern Australia ◽

Growing Environment ◽

Nitrogen Rates ◽

N Status

Straighthead is a ‘physiological’ disorder of rice, the symptoms being floret sterility, deformed florets and panicles and reduced grain yield. Straighthead in rice is difficult to investigate because of its unpredictable occurrence under field conditions. An experiment was conducted in south-eastern Australia in 1996 to investigate the effect of rate and timing of N fertilisation on growth and yield of rice. The presence of straighthead at this location gave a unique opportunity to study the influence of crop N status. This paper reports the influence of N application on straighthead symptoms during this experiment. A significant reduction of straighthead occurred with higher rates of N application. Application of 250 kg N/ha pre-flood, improved plant growth and vigour with subsequent increased uptake and accumulation of S, P, K, Mg, Cu, Mn and Zn in the plant at panicle initiation. The reduction of straighthead at high nitrogen rates may be due to improved uptake of several essential nutrients, and Cu may be a critical nutrient. This study and earlier observations have shown the application of optimal levels of pre-flood nitrogen to achieve grain yields greater than 10 t/ha may reduce straighthead severity in the Australian rice-growing environment. The results in this paper are not presented as recommendations to growers but a contribution to the currently limited literature on straighthead in Australia.

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Synthesis and Characterization of Silver-Histidine Complex Doped Montmorillonite Antibacterial Agent

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.510.757 ◽

2012 ◽

Vol 510 ◽

pp. 757-761 ◽

Cited By ~ 2

Author(s):

Shu’e Duan ◽

Yun Hui Zhai ◽

Ying Juan Qu

Keyword(s):

Antibacterial Agent ◽

Sea Water ◽

Antibacterial Activities ◽

Exchange Capacity ◽

Salt Tolerant ◽

X Ray Diffraction ◽

Ion Exchange Reaction ◽

Cationic Exchange ◽

Loading Amount

In this paper a novel colorless and salt-tolerant silver-histidine complex doped montmorillonite (Na-MMT) antibacterial agent (SHMMT) power was synthesized by ion exchange reaction using silver-histidine complex ion [Ag (his)] + as precursor, and characterized by atomic absorption spectrophotometer (AAS) and power X-ray diffraction (XRD). The antibacterial activities against Pseudoalteromonas carrageenovora were examined by a modified broth dilution test and the plate counting method. The salt-tolerant property was determined by the antibacterial activities of the sea water soaked SHMMT. The results showed that the Ag loading amount of SHMMT powder reached 1.7mmol/g, far more than the cationic exchange capacity (CEC) of Na-MMT. SHMMT powder had high bacterial activity eventhough it was soaked in the sea water for 30 days. 1

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Changes in suspension properties of structural modified montmorillonites

Cerâmica ◽

10.1590/s0366-69132001000100002 ◽

2001 ◽

Vol 47 (301) ◽

pp. 4-8 ◽

Cited By ~ 5

Author(s):

C. Volzone ◽

L. B. Garrido

Keyword(s):

Particle Size ◽

Structural Disorder ◽

Physicochemical Characteristics ◽

Exchange Capacity ◽

X Ray Diffraction ◽

Flow Properties ◽

Flow Curves ◽

Structural Modifications ◽

Fine Particle Size ◽

Cationic Exchange

Rheological changes were found in smectite (Wyoming- and Cheto-type montmorillonites) suspensions after structural modifications. The effect of the particle size and Na+ exchange on the flow curves of 6% wt/wt suspensions of smectites with and without Na2CO3 were examined. Mineralogical, structural and physicochemical characteristics were studied by X-ray diffraction (XRD), infrared spectroscopy (IR), cationic exchange capacity (CEC), Mg2+, Al3+ determinations, particle size distribution and swelling index (SI). Grinding in an oscillating mill modified the particle sizes. The montmorillonite grain size and the structural disorder increased after larger grinding times. The grinding treatment modified the apparent viscosity and the yield stress of the montmorillonite suspensions. The homoionic Na Cheto-type montmorillonite with fine particle size (obtained by grinding) increased the flow properties. Nevertheless, rheological properties were lower than those of suspensions of the Wyoming-type montmorillonite. Montmorillonite-types reacted differently with Na2CO3 additions and this behavior may be related to their structural composition. The Na2CO3 activation improved the flow properties of the original Wyoming-type montmorillonite and after 30 s grinding.

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Mineralogical characterization of natural clays from Brazilian Southeast region for industrial applications

Cerâmica ◽

10.1590/0366-69132017633662045 ◽

2017 ◽

Vol 63 (366) ◽

pp. 253-262 ◽

Cited By ~ 6

Author(s):

N. I. Alvarez Acevedo ◽

M. C. G. Rocha ◽

L. C. Bertolino

Keyword(s):

Specific Surface ◽

Clay Fraction ◽

Exchange Capacity ◽

Size Analysis ◽

Mineralogical Characterization ◽

Southeast Region ◽

Pore Size Analysis ◽

Two Samples ◽

Natural Clays ◽

Cationic Exchange

Abstract Characterization studies of clays are often performed to identify possible markets for these materials. Bearing this in mind, two samples of natural clays from the Southeast region of Brazil were studied. Conventional techniques of characterization were used. Granulometric analysis and determination of cationic exchange capacity of these clays were also performed. Nitrogen adsorption-desorption measurements were used to determine the Brunauer-Emmett-Teller specific surface area, and Barrett-Joyner-Halenda and t-plot pore size analysis were carried out. The results obtained were similar for the two clays. Both present high clay fraction (above 80 wt%) composed of illite, kaolinite and quartz minerals. Stratified illite-smectite structures were also observed. Traces of calcite were detected in one of the clay samples, while traces of montmorillonite were observed in the other sample. These results were corroborated by the low cationic exchange capacity values obtained for both clays. These clays showed good adsorptive properties, evidenced by their specific surface areas, with predominantly mesoporous structures and slit-like pores. According to their features, these clays have potential use as adsorbents to replace more expensive materials due to their easy availability and low cost.

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Yield performance of upland rice cultivars at different rates and times of nitrogen application

Revista Brasileira de Ciência do Solo ◽

10.1590/s0100-06832012000200017 ◽

2012 ◽

Vol 36 (2) ◽

pp. 475-483 ◽

Cited By ~ 3

Author(s):

José Hildernando Bezerra Barreto ◽

Ismail Soares ◽

José Almeida Pereira ◽

Antonio Marcos Esmeraldo Bezerra ◽

José Aridiano Lima de Deus

Keyword(s):

Upland Rice ◽

Oryza Sativa L ◽

Block Design ◽

N Fertilization ◽

Rice Cultivars ◽

Nitrogen Application ◽

N Application ◽

Yield Performance ◽

Randomized Block Design ◽

N Rates

Nitrogen is the most important nutrient for rice (Oryza sativa L) yields. This study aimed to evaluate the response of upland rice cultivars to N rate and application times in a randomized block design, in subdivided plots with four replications. The studied factors were five rice cultivars (BRS MG Curinga, BRS Monarca, BRS Pepita, BRS Primavera, and BRS Sertaneja), three application times (100 % at planting, 50 % at planting - 50 % at tillering and 100 % at tillering) and four N rates (0, 50, 100, and 150 kg ha-1). All cultivars responded to increased rates and different times of N application, especially BRS Primavera and BRS Sertaneja, which were the most productive when 50 % N rates were applied at sowing and 50 % at tillering. The response of cultivar BRS Monarca to N fertilization was best when 100 % of the fertilizer was applied at tillering.

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