scholarly journals A Crop Simulation Model for Tef (Eragrostis tef (Zucc.) Trotter)

Agronomy ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 817
Author(s):  
Kirsten Paff ◽  
Senthold Asseng
Keyword(s):  
Food Security ◽  
Field Experiments ◽  
N Uptake ◽  
Management Strategies ◽  
Eragrostis Tef ◽  
Photoperiod Response ◽  
Health Food ◽  
Elevated Atmospheric Co2 ◽  
Use Efficiency ◽  
Crop N Uptake

Tef is an Ethiopian staple grain that provides both food security and income for smallholders. As tef is nutritious and gluten free, it is also gaining popularity as a health food. A tef model was calibrated based on the Decision Support System for Agrotechnology Transfer’s (DSSAT) NWheat model and included parameter changes in phenology, photoperiod response, radiation use efficiency, and transpiration efficiency for both standard and elevated atmospheric CO2, based on published literature for tef and other C4 species. The new DSSAT-Tef model was compared with tef field experiments. DSSAT-Tef accurately simulated phenology and responded to changes in N supply and irrigation, but overestimated growth and occasionally yields. Simulation-observation comparisons resulted in an RMSE of 2.5 days for anthesis, 4.4 days for maturity, 2624 kg/ha (49.6%) for biomass, and 475 kg/ha (41.0%) for grain yield. Less data were available for N uptake, and the model simulated crop N uptake with an RMSE of 45 kg N/ha (46.2%) and 15 kg N/ha (37.3%) for grain N. While more data from contrasting environments are needed for further model testing, DSSAT-Tef can be used to assess the performance of crop management strategies, the suitability of tef for cultivation across growing environments, and food security.

scholarly journals Nitrogen use efficiency of 15N urea applied to wheat based on fertiliser timing and use of inhibitors

2019 ◽  
Vol 116 (1) ◽  
pp. 41-56 ◽  
Author(s):  
Ashley J. Wallace ◽  
Roger D. Armstrong ◽  
Peter R. Grace ◽  
Clemens Scheer ◽  
Debra L. Partington
Keyword(s):  
Grain Yield ◽  
N Uptake ◽  
Management Strategies ◽  
Nitrification Inhibitor ◽  
Arid Environment ◽  
Yield Response ◽  
Environmental Damage ◽  
Use Efficiency ◽  
15N Urea ◽  
Crop N Uptake

Abstract Improving fertiliser nitrogen (N) use efficiency is essential to increase productivity and avoid environmental damage. Using a 15N mass balance approach, we investigated the effects of five N fertiliser management strategies to test the hypothesis that increasing uptake of applied N by wheat improves productivity and reduces loss of N in a semi-arid environment. Three experiments were conducted between 2012 and 2014. Treatments included urea application (50 kg N/ha) at sowing with and without nitrification inhibitor (3,4-dimethylpyrazole phosphate, DMPP) and surface broadcast with and without urease inhibitor (n-butyl thiophosphoric triamide, NBPT) at the end of tillering plus an unfertilised control. It was found that deferring fertiliser application until the end of tillering decreased losses of fertiliser N (35–52%) through increasing uptake by the crop and or recovery in the soil at harvest, while maintaining yield except when rainfall following application was low. In this case, deferring application reduced fertiliser uptake (− 71%) and grain yield (− 18%) and increased recovery of N in the soil (+ 121%). Use of DMPP or NBPT reduced N loss where seasonal conditions were conducive to denitrification during winter (DMPP) and volatilisation or denitrification later in the season (NBPT). Their effect on grain yield was less significant; DMPP increased yield (+ 3–31%) in all years and NBPT increased yield (+ 7–11%) in 2 of 3 years compared to unamended urea. The majority of crop N uptake was supplied from soil reserves and as a result, crop recovery of applied N was not strongly related to grain yield response.

scholarly journals The Nitrogen Use Efficiency: Meaning and Sources of Variation—Case Studies on Three Vegetable Crops in Central Italy

2011 ◽  
Vol 21 (3) ◽  
pp. 266-273 ◽  
Author(s):  
Paolo Benincasa ◽  
Marcello Guiducci ◽  
Francesco Tei
Keyword(s):  
Field Experiments ◽  
N Uptake ◽  
Irrigation Management ◽  
Central Italy ◽  
Utilization Efficiency ◽  
Fertilizer N ◽  
Application Method ◽  
N Concentration ◽  
Sources Of Variation ◽  
Use Efficiency

Nitrogen (N) use efficiency (NUE) of crops is examined by taking into account both plant N uptake efficiency, focusing on the recovery of fertilizer-N, and the utilization efficiency of the absorbed N. The latter is further analyzed as the overall effect of the absorbed N on crop leaf area, light absorption, photosynthesis, crop growth, biomass partitioning, and yield. The main sources of variation for the NUE of crops are considered, and several of them are discussed based on results from field experiments carried out at the University of Perugia (central Italy) between 1991 and 2008 on sweet pepper (Capsicum annuum), lettuce (Lactuca sativa), and processing tomato (Solanum lycopersicum). More specifically, the effects of species, cultivar, fertilizer-N rate, form and application method (mineral and organic fertilization, green manuring, fertigation frequency), and sink limitation are reported. Implications for residual N in the soil and leaching risks are also discussed. The fertilizer-N rate is the main factor affecting crop NUE for a given irrigation management and rainfall regime. Indeed, avoiding over fertilization is the first and primary means to match a high use efficiency and economic return of fertilizer-N with limited environmental risks from nitrate leaching. The form and application method of fertilizer-N also may affect the NUE, especially in the case of limiting or overabundant N supply. Particularly, high fertigation frequency increased the recovery of fertilizer-N by the crop. It is suggested that species-specific curves for critical N concentration (i.e., the minimum N concentration that allows the maximum growth) can be the reference to calibrate the quick tests used to guide dynamic fertilization management, which is essential to achieve both the optimal crop N nutritional status and the maximum NUE.

Influence of Phosphorus Fertilizers Application on Phosphorus use Efficiency and Grain Protein of Winter Wheat in Alkaline-Calcareous Soil, Southern Algeria

2019 ◽  
Author(s):  
N Boukhalfa Deraoui ◽  
L Hanifi Mekliche ◽  
A Mekliche ◽  
H Cheloufi ◽  
S Babahani
Keyword(s):  
Winter Wheat ◽  
Field Experiments ◽  
N Uptake ◽  
Ammonium Phosphate ◽  
Grain Protein Content ◽  
Phosphorus Fertilization ◽  
Grain Protein ◽  
Phosphorus Use Efficiency ◽  
Use Efficiency ◽  
Single Super Phosphate

hree field experiments (2008 to 2011) were conducted to evaluate the ability of winter wheat (Triticum durum Desf. var. Carioca) to utilize and acquire soil phosphorus and nitrogen under different sources of phosphate fertilizers (Fosfactyl, Single super phosphate and Mono-ammonium-phosphate) and rates of applications (30, 60, 90 and 120 kg Pha-1) with a fixed level of nitrogen fertilization. Results revealed a significant effect of P rates on phosphorus use efficiency (PUE) and nitrogen use efficiency (NUE); however, P sources fertilizer had non-significant effect in all three cropping seasons. PUE and NUE decreased markedly with increasing P supply that did not result in an improvement of P and N uptake. Grain protein content was significantly influenced by phosphorus fertilization in 2008-09. The best values were obtained by Single super phosphate and P rate 60 kg ha-1.

scholarly journals   Effects of nitrogen application stage on grain yield and nitrogen use efficiency of high-yield summer maize

2012 ◽  
Vol 58 (No. 5) ◽  
pp. 211-216 ◽  
Author(s):  
P. Lü ◽  
J.W. Zhang ◽  
L.B. Jin ◽  
W. Liu ◽  
S.T. Dong ◽  
...  
Keyword(s):  
Field Experiments ◽  
N Uptake ◽  
High Yield ◽  
Summer Maize ◽  
N Application ◽  
Total N ◽  
Leaf Stage ◽  
Application Method ◽  
Use Efficiency ◽  
Jointing Stage

This study aims to explore the optimum nitrogen (N) application method by analyzing effects of variable N application stages and ratios on the N absorption and translocation of high-yield summer maize (DH661). The study included field experiments and <sup>15</sup>N isotopic dilutions for pot experiments. Results showed that the yield was not increased in a one-off N application at the jointing stage. The uptake of fertilizer-derived N in the grain increased with the increasing of N applied times. Compared to a single or double application, total N uptake (N<sub>up</sub>) and biomass increased significantly by supplying N at the six-leaf stage (V6), ten-leaf stage (V10) and 10 days after anthesis in ratios of 3:5:2 and 2:4:4. The fertilizer-derived recovery rates were 67.5% and 78.1%, respectively. The uptake and utilization of fertilizer-derived N was enhanced by increasing the recovery rate of N supplied after anthesis, and reducing the absorption of soil-derived N. Therefore, the 2:4:4 application ratios was the optimal N application method. &nbsp;

scholarly journals The Role of Nitrogen-Efficient Cultivars in Sustainable Agriculture

2001 ◽  
Vol 1 ◽  
pp. 61-69 ◽  
Author(s):  
Franz Weisler ◽  
Torsten Behrens ◽  
Walter J. Horst
Keyword(s):  
Oilseed Rape ◽  
Field Experiments ◽  
N Uptake ◽  
Management Strategies ◽  
Growing Season ◽  
Utilization Efficiency ◽  
High Uptake ◽  
Uptake Efficiency ◽  
N Supply ◽  
N Efficiency

To improve nitrogen (N) efficiency in agriculture, integrated N management strategies that take into consideration improved fertilizer, soil, and crop management practices are necessary. This paper reports results of field experiments in which maize (Zea mays L.) and oilseed rape (Brassica napus L.) cultivars were compared with respect to their agronomic N efficiency (yield at a given N supply), N uptake efficiency (N accumulation at a given N supply), and N utilization efficiency (dry matter yield per unit N taken up by the plant). Under conditions of high N supply, significant differences among maize cultivars were found in shoot N uptake, soil nitrate depletion during the growing season, and the related losses of nitrate through leaching after the growing season. Experiments under conditions of reduced N supply indicated a considerable genotypic variation in reproductive yield formation of both maize and oilseed rape. High agronomic efficiency was achieved by a combination of high uptake and utilization efficiency (maize), or exclusively by high uptake efficiency (rape). N-efficient cultivars of both crops were characterized by maintenance of a relatively high N-uptake activity during the reproductive growth phase. In rape this trait was linked with leaf area and photosynthetic activity of leaves. We conclude that growing of N-efficient cultivars may serve as an important element of integrated nutrient management strategies in both low- and high-input agriculture.

RELATIVE PERFORMANCE OF BORON, SULPHUR AND ZINC COATINGS ONTO PRILLED UREA FOR INCREASING PRODUCTIVITY AND NITROGEN USE EFFICIENCY IN MAIZE

2017 ◽  
Vol 54 (4) ◽  
pp. 577-591 ◽  
Author(s):  
VIJAY POONIYA ◽  
YASHBIR SINGH SHIVAY ◽  
MADAN PAL ◽  
RADHIKA BANSAL
Keyword(s):  
Nitrogen Use Efficiency ◽  
Field Experiments ◽  
N Uptake ◽  
Maize Yield ◽  
Nitrogen Use ◽  
Total N ◽  
Prilled Urea ◽  
Zn Uptake ◽  
Coated Urea ◽  
Use Efficiency

SUMMARYDeficiencies of micro (Zn, B) and secondary (S) nutrients are well-documented in soil as well as in cereal crops, leading to decreased crop yields and low nutritional quality of food. We evaluated the effects of coated urea on maize yield, N and Zn uptake, and input cost relationships. Field experiments were conducted on maize to test boron-coated (BCU), sulphur-coated (SCU) and zinc-coated urea (ZnCU) during 2013 and 2014. On the basis of 2 years’ average data, the highest grain yield was achieved with 0.5% BCU, 5% SCU and 2.5% ZnCU as zinc sulphate hepta hydrate. These treatments increased yields by 5.4, 12.8 and 9.9% over prilled urea (PU), respectively. Application of 0.5% BCU (supplying 1.4 kg B ha−1), 5% SCU (supplying 14.1 kg S ha−1) and 2.5% ZnCU (supplying 7.05 kg Zn ha−1) registered the highest N concentrations and uptake in grain and stover. Total N uptake (grain + stover) was increased by 7.6, 16.7 and 17.1% with BCU, SCU and ZnCU treatments over PU. As compared to PU, Zn concentration in maize grain was significantly higher and total Zn uptake (grain + stover) increased by 32.4% with 2.5% ZnCU. Coated urea materials also enhanced the partial factor productivity (PFPN), agronomic efficiency (AEN), recovery efficiency (REN) and harvest index (HIN) over those of PU. From the economic viewpoint this study suggests that coating of urea with 0.3% boron, 5% sulphur or 2% zinc gives maximum net returns and benefit-cost ratio. Our data indicate that coating of B, Zn and S onto urea increases maize yield, profitability and nitrogen use efficiency in the western Indo-Gangetic plains of India.

scholarly journals Insecticidal Properties of Capsaicinoids and Glucosinolates Extracted from Capsicum chinense and Tropaeolum tuberosum

Insects ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 132 ◽  
Author(s):  
José L. Claros Cuadrado ◽  
Elder O. Pinillos ◽  
Richard Tito ◽  
Carlos Seguil Mirones ◽  
Norma N. Gamarra Mendoza
Keyword(s):  
Food Security ◽  
Pest Management ◽  
Field Experiments ◽  
Management Strategies ◽  
Capsicum Chinense ◽  
Synthetic Pesticides ◽  
Short Time ◽  
Potential Use ◽  
A Current ◽  
Tropaeolum Tuberosum

Food security and biodiversity conservation are threatened by the emergence and spread of pest and pathogens, and thus there is a current need to develop pest management strategies that are sustainable and friendly to the environment and human health. Here, we performed laboratory and field bioassays to evaluate the insecticidal effects of several concentrations of capsaicinoids and glucosinolates (separately and mixed) on an aphid pest (Aphis cytisorum). The capsaicinoids were extracted from the fruits of Capsicum chinense and glucosinolates from the tubers of native Andean crop Tropaeolum tuberosum. We found that both capsaicinoids and glucosinolates have a biocidal effect on A. cytisorum, acting within a fairly short time. Under laboratory conditions, the toxicity of the compounds increased in relation to their concentrations, causing a high percentage of mortality (83–99%) when the aphids were exposed to dilutions of 10% capsaicinoids, 75–100% glucosinolates, or a mixture of 10% capsaicinoids and 90% glucosinolates. The mortality of aphids sprayed in the field with 5% capsaicinoids, 50% glucosinolates, or with a mixture of 5% capsaicinoids and 45% glucosinolates reached 87–97%. Results obtained from laboratory and field experiments were consistent. Our results suggest the potential use of bioinsecticides based on capsaicinoids and/or glucosinolates as an effective alternative to synthetic pesticides.

Etridiazole may conserve applied nitrogen and increase yield of irrigated cotton

Soil Research ◽  
1994 ◽  
Vol 32 (6) ◽  
pp. 1287 ◽  
Author(s):  
IJ Rochester ◽  
H Gaynor ◽  
GA Constable ◽  
PG Saffigna
Keyword(s):  
Field Experiments ◽  
N Uptake ◽  
Nitrification Inhibitor ◽  
Lint Yield ◽  
Cotton Production ◽  
N Loss ◽  
Cotton Crop ◽  
Anhydrous Ammonia ◽  
Crop N Uptake ◽  
Crop Maturity

Recovery of applied N is often poor in irrigated cotton production in Australia, due to N loss through biological denitrification in the heavy clay soils. We envisaged that the N loss through denitrification could be reduced by limiting the soil nitrate concentration by applying a nitrification inhibitor with the fertilizer. We applied the nitrification inhibitor etridiazole in three field experiments in two cotton-growing seasons (1991-1993). The nitrification of ammonium-N applied as urea or anhydrous ammonia, the cotton crop N uptake and lint yield were monitored; recovery of 15N-labelled urea applied to microplots was assessed at crop maturity. In the first experiment, urea was applied at rates of 0 and 80 kg N ha-1 with etridiazole (applied as Terrazole EC). The recommended etridiazole rate (300 g ha-1) was compared with nil, half and double that rate. In the fertilized treatments where etridiazole was applied, nitrification of ammonium was retarded for more than 2 months, cotton crop N uptake was increased by 28% at maturity and lint yield increased by 18%, relative to the control. Etridiazole application had little effect on soil N concentrations, crop N uptake or lint yield in the unfertilized treatments. Fertilizer recovery was significantly improved from 35 to 50% with etridiazole application. The second experiment (in the following year) was conducted under commercial conditions. Etridiazole was applied with urea at 86, 119 and 154 kg N ha-1. As in Experiment 1, nitrification was delayed, crop N uptake was enhanced at crop maturity and lint yield was significantly increased by 46 kg ha-1 (3% greater than the control) with etridiazole application. In the third experiment, anhydrous ammonia was applied at rates from 0 to 175 kg N ha-1, with and without etridiazole. Recovery of 15N-labelled urea was not significantly altered by etridiazole application from the relatively high (69%) recovery in the control treatment. Maximum lint yield was 130 kg ha-1 (6.9%) higher in the etridiazole treatments, but required the application of additional N to achieve it. These experiments indicated that etridiazole was cost-effective in increasing lint yield of irrigated cotton and conserved applied N where substantial denitrification loss occurred.

scholarly journals Split application of reduced nitrogen rate improves nitrogen uptake and use efficiency in sweetpotato

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Xiangbei Du ◽  
Min Xi ◽  
Lingcong Kong
Keyword(s):  
Field Experiments ◽  
Developmental Stages ◽  
N Uptake ◽  
Partition Ratio ◽  
Growth Stages ◽  
Storage Root ◽  
Split Application ◽  
N Application ◽  
Use Efficiency ◽  
Partial Factor Productivity

Abstract Splitting nitrogen (N) application is beneficial for enhancing sweetpotato growth and promoting optimum yields under reduced N rates; however, studies concerning how split N can affect sweetpotato N dynamics and utilization are limited. Field experiments were conducted from 2015 to 2016 to determine how split N application affects sweetpotato N uptake and N use efficiency (NUE) under a reduced N rate. Two cultivars (Xushu 22 and Shangshu 19) were planted under four N treatments, a conventional basal application of 100 kg N ha−1 (100:0), a basal application of 80 kg N ha−1 (80:0), two equal split applications of 80 kg N ha−1 (basal and 35 days after transplanting, 40:40) and a N omission treatment (N0). Data from two years revealed that sweetpotato yields decreased at a reduced 20% N rate with a basal application (80:0); however, the reduced 20% N rate with a split application (40:40) significantly increased the yield by 16.6–19.0%. Although the 80:0 treatment decreased sweetpotato N uptake, the 40:40 treatment increased the N uptake by increasing the N uptake rate and prolonging the duration of the fast N uptake phase. In comparison to the basal application, the split N application used N more efficiently, showing consistently higher levels of agronomic use efficiency, recovery efficiency, physiological efficiency and partial factor productivity. NUEs under split N improved due to increased N uptake during the middle and late growth stages and a higher N partition ratio to the storage root. The above results indicate that split N application provides better N for crop developmental stages and is recommended as an alternative approach to simultaneously increasing storage root yield and NUE under a reduced N rate in sweetpotato production in China.

Evaluation of different nitrogen use efficiency indices using field-grown green bell peppers (Capsicum annuum L.)

2007 ◽  
Vol 87 (3) ◽  
pp. 565-569 ◽  
Author(s):  
Laura L Van
Keyword(s):  
Field Experiments ◽  
N Uptake ◽  
Nutrient Use Efficiency ◽  
N Fertilization ◽  
Yield Response ◽  
Marketable Yield ◽  
Mineral N ◽  
N Application ◽  
Bell Peppers ◽  
Use Efficiency

The effects of increasing nitrogen (N) fertilization on N use efficiency (NUE) and yield of green bell pepper were assessed in five field experiments over 2004 and 2005. These data were used to evaluate and contrast conclusions drawn from among 12 different NUE indices. In two diferent years (i.e., cool/wet vs. warm/dry), marketable yield response to N application was either positive or no response was observed. Total percent N in the fruit and shoot was lower in non-fertilized plants compared with plants grown in plots that received 70 or 210 kg N ha-1. There were considerable differences among locations in soil mineral N, yield, NUE, and plant N uptake and removal. For all eight fertilizer- and soil-based NUE indices assessed, NUE decreased as N application increased. However, for plant-based NUE indices, there was no difference in NUE values between N treatments. Thus, the interpretation and applicability of NUE depends on the goals of the research and the index used. Key words: Nutrient use efficiency, green bell peppers, harvest index, nitrogen, fertilizer, vegetable

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