scholarly journals Improving High-Latitude Rice Nitrogen Management with the CERES-Rice Crop Model

Agronomy ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 263 ◽  
Author(s):  
Jing Zhang ◽  
Yuxin Miao ◽  
William Batchelor ◽  
Junjun Lu ◽  
Hongye Wang ◽  
...  
Keyword(s):  
High Latitude ◽  
Management Strategies ◽  
Growing Season ◽  
Weather Data ◽  
Factor Productivity ◽  
Rice Varieties ◽  
Partial Factor Productivity ◽  
N Management ◽  
N Rates ◽  
Partial Factor

Efficient use of nitrogen (N) fertilizer is critically important for China’s food security and sustainable development. Crop models have been widely used to analyze yield variability, assist in N prescriptions, and determine optimum N rates. The objectives of this study were to use the CERES-Rice model to simulate the N response of different high-latitude, adapted flooded rice varieties to different types of weather seasons, and to explore different optimum rice N management strategies with the combinations of rice varieties and types of weather seasons. Field experiments conducted for five N rates and three varieties in Northeast China during 2011–2016 were used to calibrate and evaluate the CERES-Rice model. Historical weather data (1960–2014) were classified into three weather types (cool/normal/warm) based on cumulative growing degree days during the normal growing season for rice. After calibrating the CERES-Rice model for three varieties and five N rates, the model gave good simulations for evaluation seasons for top weight (R2 ≥ 0.96), leaf area index (R2 ≥ 0.64), yield (R2 ≥ 0.71), and plant N uptake (R2 ≥ 0.83). The simulated optimum N rates for the combinations of varieties and weather types ranged from 91 to 119 kg N ha−1 over 55 seasons of weather data and were in agreement with the reported values of the region. Five different N management strategies were evaluated based on farmer practice, regional optimum N rates, and optimum N rates simulated for different combinations of varieties and weather season types over 20 seasons of weather data. The simulated optimum N rate, marginal net return, and N partial factor productivity were sensitive to both variety and type of weather year. Based on the simulations, climate warming would favor the selection of the 12-leaf variety, Longjing 21, which would produce higher yield and marginal returns than the 11-leaf varieties under all the management strategies evaluated. The 12-leaf variety with a longer growing season and higher yield potential would require higher N rates than the 11-leaf varieties. In summary, under warm weather conditions, all the rice varieties would produce higher yield, and thus require higher rates of N fertilizers. Based on simulation results using the past 20 years of weather data, variety-specific N management was a practical strategy to improve N management and N partial factor productivity compared with farmer practice and regional optimum N management in the study region. The CERES-Rice crop growth model can be a useful tool to help farmers select suitable precision N management strategies to improve N-use efficiency and economic returns.

Evaluating a Crop Circle active sensor-based in-season nitrogen management algorithm in different winter wheat cropping systems

2017 ◽  
Vol 8 (2) ◽  
pp. 364-367 ◽  
Author(s):  
L. Zhou ◽  
G. Chen ◽  
Y. Miao ◽  
H. Zhang ◽  
Z. Chen ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Cropping Systems ◽  
Management Strategies ◽  
Cropping System ◽  
Management Algorithm ◽  
Active Sensor ◽  
Partial Factor Productivity ◽  
N Management ◽  
Partial Factor ◽  
On Farm

The objective of this study was to evaluate the performance of a Crop Circle sensor-based precision nitrogen (N) management (PNM) strategy in different winter wheat cropping systems under on-farm conditions in North China Plain (NCP). Four farmer’s fields were selected for on-farm experiments in Laoling County, Shandong Province of NCP in 2015-2016. In each field, the PNM strategy was evaluated in two winter wheat cropping systems: farmer’s conventional management (FCM) and regional optimum crop management (ROCM). In each cropping system, there were two N management strategies: 1) FCM or ROCM; 2) PNM. The results indicated that the PNM strategy significantly increased partial factor productivity (PFP) by 29% in the FCM system, but did not have any significant improvement in the ROCM system. The ROCM system, using either regional optimum N management or PNM, significantly increased both grain yield and PFP than the FCM system.

Evaluation of the CERES-Rice Model for Precision Nitrogen Management for Rice in Northeast China

2017 ◽  
Vol 8 (2) ◽  
pp. 328-332
Author(s):  
J. Zhang ◽  
Y. Miao ◽  
W.D. Batchelor
Keyword(s):  
Northeast China ◽  
Weather Data ◽  
Cool Season ◽  
Use Efficiency ◽  
Optimum N Rate ◽  
Management Recommendations ◽  
N Management ◽  
N Rates ◽  
N Use

Over-application of nitrogen (N) in rice (Oryza sativaL.) production in China is common, leading to low N use efficiency (NUE) and high environmental risks. The objective of this work was to evaluate the ability of the CERES-Rice crop growth model to simulate N response in the cool climate of Northeast China, with the long term goal of using the model to develop optimum N management recommendations. Nitrogen experiments were conducted from 2011–2015 in Jiansanjiang, Heilongjiang Province in Northeast China. The CERES-Rice model was calibrated for 2014 and 2015 and evaluated for 2011 and 2013 experiments. Overall, the model gave good estimations of yield across N rates for the calibration years (R2=0.89) and evaluation years (R2=0.73). The calibrated model was then run using weather data from 2001–2015 for 20 different N rates to determine the N rate that maximized the long term marginal net return (MNR) for different N prices. The model results indicated that the optimum mean N rate was 120–130 kg N ha–1, but that the simulated optimum N rate varied each year, ranging from 100 to 200 kg N ha–1. Results of this study indicated that the CERES-Rice model was able to simulate cool season rice growth and provide estimates of optimum regional N rates that were consistent with field observations for the area.

scholarly journals Comparative Study on Gluten Protein Composition of Ancient (Einkorn, Emmer and Spelt) and Modern Wheat Species (Durum and Common Wheat)

Foods ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 409 ◽  
Author(s):  
Geisslitz ◽  
Longin ◽  
Scherf ◽  
Koehler
Keyword(s):  
Durum Wheat ◽  
Common Wheat ◽  
Protein Composition ◽  
Total Protein Content ◽  
Gluten Protein ◽  
Wheat Species ◽  
Factor Productivity ◽  
Modern Wheat ◽  
Partial Factor Productivity ◽  
Partial Factor

The spectrophotometric Bradford assay was adapted for the analysis of gluten protein contents (gliadins and glutenins) of spelt, durum wheat, emmer and einkorn. The assay was applied to a set of 300 samples, including 15 cultivars each of common wheat, spelt, durum wheat, emmer and einkorn cultivated at four locations in Germany in the same year. The total protein content was equally influenced by location and wheat species, however, gliadin, glutenin and gluten contents were influenced more strongly by wheat species than location. Einkorn, emmer and spelt had higher protein and gluten contents than common wheat at all four locations. However, common wheat had higher glutenin contents than einkorn, emmer and spelt resulting in increasing ratios of gliadins to glutenins from common wheat (< 3.8) to spelt, emmer and einkorn (up to 12.1). With the knowledge that glutenin contents are suitable predictors for high baking volume, cultivars of einkorn, emmer and spelt with good predicted baking performance were identified. Finally, spelt, emmer and einkorn were found to have a higher nitrogen partial factor productivity than common and durum wheat making them promising crops for a more sustainable agriculture.

Impact of privatisation on the financial and economic performance of European airports

2006 ◽  
Vol 110 (1106) ◽  
pp. 197-213 ◽  
Author(s):  
H.-A. Vogel
Keyword(s):  
Ownership Structure ◽  
Operating Efficiency ◽  
Data Envelopment ◽  
Factor Productivity ◽  
Financial Ratio ◽  
Capital Productivity ◽  
Sample Data ◽  
Publicly Owned ◽  
Partial Factor Productivity ◽  
Partial Factor

Abstract This paper assesses the financial performance of 35 European airports for the decade 1990 to 2000, comparing those subject to partial or full privatisation with those still in public ownership. In contrast to earlier research, the outcomes of partial factor productivity (PFP), financial ratio (FRA) and data envelopment analysis (DEA) are evaluated, in order to investigate differences attributable to the degree of privatisation. Changes in performance after a change in ownership structure are reviewed. The analysis of sample data reveals economically meaningful and statistically significant differences between publicly owned and privatised airports. The major differences lie in operating efficiency, capital productivity and capital structure. Although partially and fully privatised airports operate more efficiently, this does not translate into significantly higher returns on shareholders’ funds. Due to their at least indirectly government-backed credit standing, publicly owned airport companies can assume more debt relative to their respective equity. This results in considerably higher gearing and financial leverage, which compensates for the comparatively low return rate on assets.

scholarly journals Evaluation of N Efficiency Using Prilled Urea and Urea Super Granules in T. Aman Rice

2015 ◽  
Vol 18 (1) ◽  
pp. 59-63 ◽  
Author(s):  
J Hussain ◽  
M Salim ◽  
MA Siddique ◽  
M Khatun ◽  
S Islam
Keyword(s):  
Nitrogen Use Efficiency ◽  
Rice Varieties ◽  
Marginal Rate ◽  
Nitrogen Use ◽  
Prilled Urea ◽  
N Efficiency ◽  
Use Efficiency ◽  
Marginal Rate Of Return ◽  
Partial Factor Productivity ◽  
Partial Factor

An experiment was conducted at the Experimental field of Department of Agronomy, Bangladesh Agricultural University, Mymensingh, during June to December 2007 to evaluate the nitrogen use efficiency of transplant aman rice using prilled urea (PU) and urea super granule (USG). Three rice varieties (BR11, BRRI dhan30 and BRRI dhan39) were compared at three doses of nitrogen, i.e., PU@125 kg N ha-1, USG @170 kg N ha-1 and USG @ 70 kg N ha-1 in a Randomized Complete Block (RCB) design with three replications. USG each weighing 1 g and 2.6 g were placed manually at the depth of 8-10 cm in the middle of four hills in alternate rows at 12 days after transplanting and PU applied in split applications. The rice var. BR11 at USG @70 kg N ha-1 has produced the maximum grain yield (4.75 t ha-1) which was statistically identical to BRRI dhan30 at USG @ 70 kg N ha-1 (1 g pellet-1). The highest nitrogen use efficiency, partial factor productivity and marginal rate of return (1966%) were recorded from the treatment of BR11 at USG @ 70 kg N ha-1.Bangladesh Agron. J. 2015, 18(1): 59-63

scholarly journals Nitrogen Management Strategies of Tillage and No-Tillage Wheat Following Rice in the Yangtze River Basin, China: Grain Yield, Grain Protein, Nitrogen Efficiency, and Economics

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 155 ◽  
Author(s):  
Jinfeng Ding ◽  
Fujian Li ◽  
Tao Le ◽  
Peng Wu ◽  
Min Zhu ◽  
...  
Keyword(s):  
Grain Yield ◽  
Management Strategies ◽  
Soil Conditions ◽  
Grain Protein ◽  
No Tillage ◽  
Total N ◽  
Evaluation Indexes ◽  
Net Returns ◽  
N Management ◽  
N Rates

In the rice-wheat rotation system, conventional culturing of high yield rice results in poor soil conditions and excessive residues, which negatively affect wheat growth. Tillage and nitrogen (N) use are being sought to address this problem. In order to propose a suitable tillage method and corresponding N management strategy, the influence of three tillage methods (i.e., plow tillage followed by rotary tillage (PR), rotary tillage twice (RR), and no-tillage (NT)) and nine forms of N management strategies (i.e., three total N rates × three N-splitting schemes) were investigated in a field experiment from 2016 to 2017 (2017) and 2017 to 2018 (2018), using grain yield, grain protein content (GPC), N uptake efficiency (NUpE), and net returns as evaluation indexes. Grain yield, GPC, and net returns were lower in 2017 than 2018, likely as a result of weak seedling growth caused by high soil moisture before and after seeding. In 2017, NT achieved higher grain yield, NUpE, and net returns compared to PR or RR, while grain yield and net returns were higher under tillage in 2018, especially PR. Increased total N rates (210–270 kg ha−1) promoted all evaluation indexes, but suitable timing and corresponding rates of N application are dependent on the environment. These results indicate that the combination of NT and applying N at lower rates and only a few times (i.e., 168 and 72 kg ha−1 applied at pre-sowing and when flag leaves are visible) when the soil is not suitable for tillage is the best method for cutting costs and improving benefits. Under suitable conditions for tillage, PR and intensive management strategies (i.e., 135, 27, 54, and 54 kg ha−1 applied at pre-sowing, four-leaf, jointing, and booting, respectively) could be adopted to increase overall yield, quality, and benefits.

scholarly journals Remedial Application of Urea Eliminates Yield Losses in Wheat Waterlogged during Stem Elongation

Agriculture ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 23
Author(s):  
Jinfeng Ding ◽  
Peng Liang ◽  
Desheng Guo ◽  
Dejun Liu ◽  
Mingxiao Yin ◽  
...  
Keyword(s):  
Grain Yield ◽  
Stem Elongation ◽  
N Uptake ◽  
Urea Solution ◽  
Yield Losses ◽  
Factor Productivity ◽  
Kernel Number ◽  
Total N ◽  
Partial Factor Productivity ◽  
Partial Factor

Waterlogging remains a critical constraint to wheat production in areas with high rainfall. Exogenous application of nitrogen (N) can effectively diminish the adverse effects of waterlogging, but varies with specific events. To provide highly efficient remedial strategies, this pot study investigated the effects of urea application following 10 days of waterlogging initialing at the stem elongation stage (Zadoks growth stage, GS33). The remedial measures included foliar spray of urea solution at a single dose (0.108 g urea per pot) at the 0th day after finishing waterlogging (FU1) and twice at the 0th and 7th day (FU2), and soil surface spray of urea solution at single and double doses when soil water content was approximately 80% of field capacity (SU1 and SU2, respectively). Waterlogging significantly reduced grain yield, total N uptake, and N partial factor productivity (by 11%, 18%, and 11%, respectively), but subsequent remedial measures improved these to variable degrees. Reduction in grain yield owing to waterlogging could be effectively alleviated and even eliminated using these remediations. Grain yield and N partial factor productivity were higher under FU2 and SU2 than FU1 and SU1. Among all treatments, plants under SU2 exhibited the highest total N uptake and top-dressing N recovery. Diminished yield losses were attributed to (1) increased kernel number per spike resulting from increased spikelet fertility and kernel number per spikelet and (2) increased photosynthetic production by delaying senescence (improved chlorophyll content and maintained green leaf area) of the top leaves. This study suggests that urea application for a brief period of time following waterlogging during the stem elongation stage has remarkable remedial effects.

scholarly journals INTEGRATED NUTRIENT MANAGEMENT OF PEARL MILLET IN THE SAHEL COMBINING CATTLE MANURE, CROP RESIDUE AND MINERAL FERTILIZER

2008 ◽  
Vol 44 (4) ◽  
pp. 453-472 ◽  
Author(s):  
PIERRE B. I. AKPONIKPE ◽  
KARLHEINZ MICHELS ◽  
CHARLES L. BIELDERS
Keyword(s):  
Synergistic Effect ◽  
Grain Yield ◽  
Pearl Millet ◽  
Nutrient Management ◽  
Mineral Fertilizer ◽  
Integrated Nutrient Management ◽  
Factor Productivity ◽  
Yield Increase ◽  
Partial Factor Productivity ◽  
Partial Factor

SUMMARYIn the Sahelian zone of Niger, there is a need to develop guidelines for integrated nutrient management, which relies on the potential nutrient sources of manure, pearl millet residue and mineral fertilizers. A fully factorial on-station experiment was conducted during the 1994 and 1995 rainy seasons at Sadoré, Niger, combining application of: (i) broadcast millet residue (300, 900 and 2700 kg ha−1), (ii) broadcast cattle manure (300, 900 and 2700 kg ha−1) and (iii) mineral fertilizer (unfertilized control, 15 kg N ha−1 + 4.4 kg P ha−1 and 45 kg N ha−1 + 13.1 kg P ha−1). Manure and fertilizer increased millet yields in both years whereas residue was effective in 1995 only. The effect of manure and residue were additive, as was the effect of manure and fertilizer but only up to 50 kg N ha−1. However in 1995, the response to fertilizer was approximately doubled in the presence of 900 or 2700 kg residue ha−1 compared to fertilizer with 300 kg ha−1 residue, indicating a strong synergistic effect. This synergistic effect was reflected in the partial factor productivity of nitrogen and phosphorous in both years. Two treatment combinations stand out as particularly relevant based on yield, partial factor productivity and nutrient balance criteria: 2700 kg manure ha−1 combined with (i) 300 kg residue and no fertilizer (95% grain yield increase); (ii) 900 kg residue ha−1 and 15 kg N + 4 kg P ha−1 (132% grain yield increase). There is a need for similar, long-term experiments to confirm the present results.

STRUCTURE, EMPLOYMENT AND PRODUCTIVITY GROWTH IN THE INDIAN UNORGANIZED MANUFACTURING SECTOR: AN INDUSTRY LEVEL ANALYSIS

2011 ◽  
Vol 56 (03) ◽  
pp. 349-376 ◽  
Author(s):  
S. N. RAJESH RAJ
Keyword(s):  
Labor Productivity ◽  
Technological Progress ◽  
Manufacturing Sector ◽  
Capital Intensity ◽  
Factor Productivity ◽  
Capital Productivity ◽  
Size Growth ◽  
Partial Factor Productivity ◽  
Partial Factor ◽  
Level Analysis

The paper analyzes the size, growth and productivity performance of the unorganized manufacturing sector in India during the 1978–1979 to 2000–2001 period. The study shows evidence of an increase in the size of the sector with a slowdown in the reforms period. Evidence indicates that the rate of growth varies widely across the two-digit industries but the variation in growth rate is smaller during the 1990s. Textiles and machinery goods were the fastest growing segments of India's unorganized manufacturing sector in the reforms period. The partial factor productivity approach shows that labor productivity has improved in 2000–2001 over 1978–1979 while capital productivity reported a decline in the same period. The sector, on the other hand, registered a fall in total factor productivity (TFP) during the reforms period. It is found that technological progress has been the main contributor to the growth in TFP in the prereforms period while technical regress contributed to the decline in TFP in the reforms period. A completely different picture is noticed since the mid-1990s when the sector made significant progress in TFP primarily attributed to technological progress which outweighed the decline in technical efficiency. It is also found that capital intensity is an essential factor augmenting labor productivity levels in the sector, which is important for improving the wages paid to the workers in the sector.

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