The influence of rotation systems on long-term trends in wheat yield

1972 ◽  
Vol 23 (6) ◽  
pp. 935 ◽  
Author(s):  
BR Elliott ◽  
R Jardine
Keyword(s):  
Regression Model ◽  
Wheat Yield ◽  
Multiple Regression Model ◽  
Climatic Fluctuations ◽  
Yield Increase ◽  
Factors Influencing ◽  
Long Term Trends ◽  
Wheat Stubble ◽  
Yield Trends

The wheat yield trends of six rotation systems were examined over the 29-year period 1940-1968. The multiple regression model used incorporated variables to minimize the effect of climatic fluctuations and trends. All the rotation systems examined showed positive, almost linear, yield increases over the first 19 years (1940-1958). Over the final 10 years (1959-1968) those systems including a pasture phase continued to show a linear yield increase; other three-course systems (fallow, wheat, stubble crop) showed a less than linear yield increase; while the two-course system (fallow, wheat) showed a 22% yield decline. Possible factors influencing the yield trends are briefly discussed.

Wheat yield response to rainfall in a long-term multi-rotation experiment in the Victorian Wimmera

1995 ◽  
Vol 35 (7) ◽  
pp. 951 ◽  
Author(s):  
MC Hannah ◽  
GJ O'Leary
Keyword(s):  
Wheat Yield ◽  
Field Pea ◽  
Yield Response ◽  
Yield Data ◽  
Long Term Trends ◽  
Quadratic Response ◽  
Wheat Stubble ◽  
High Yields ◽  
Crop Sequence

Seventy-six years of wheat yield data from a long-term rotation experiment at Dooen in the Victorian Wimmera were analysed to describe the response of wheat yield to seasonal rainfall, crop sequence, and time. Wheat yields from 7 different 1- to 4-course rotations involving wheat, barley, oat, field pea, grass pasture and fallow were compared as a function of growing-season (May-November) rainfall. The field layout had no within-year replication, but each phase of each rotation was represented once in each year. An approximate quadratic response of wheat yield to both current year and previous year May-November rainfall was observed for each rotation. Previous year May-November rainfall boosted wheat yields grown on fallow, but decreased the yield of wheat grown on field pea or wheat stubble. Highest wheat yields followed fallow preceded by pasture, high yields followed fallow preceded by a cereal, moderate yields followed field pea, and low yields occurred for continuous wheat. Long-term trends in wheat yields adjusted for rainfall depended on crop sequence and fluctuated more in the non-fallow, 3-course rotations. Over the 76 years, average yield declined in all rotations except the continuous wheat, which was always low, but there was evidence that yield of all continuous cropped rotations had increased during the last 2 decades.

Are Top Private Banks Digging the Invisible Holes in the Balance Sheet?

2020 ◽  
pp. 234-255
Author(s):  
Hariom Gurjar ◽  
Akhilesh Tripathi ◽  
Neha Mathur ◽  
Yamini Saraswat
Keyword(s):  
Regression Model ◽  
Balance Sheet ◽  
Multiple Regression Model ◽  
Vital Role ◽  
Financial Resources ◽  
Logical Connection ◽  
Factors Influencing ◽  
Private Banks

Off-balance-sheet activity played a vital role in helping banks limit long-term financial resources in the balance sheet report and increase the bank's profitability worldwide. The authors explored the determinates of OBS items with banking and economic factors influencing off-balance items in the measurement of banks' output of selected large banks in India for the duration of 2008 to 2017. This study used a multiple regression model to describe the logical connection between the role of OBS and its various determinants like bank size, CRAR loan SLR, NNPA, NIM, ROA, GDP, inflation for the said period. This study found that bank size and NIM were positively affected the OBS activities, whereas CRAR and loan negatively affected the OBSA of selected private sector banks.

Holocene Climate Variability in Antarctica Based on 11 Ice-Core Isotopic Records

2000 ◽  
Vol 54 (3) ◽  
pp. 348-358 ◽  
Author(s):  
Valérie Masson ◽  
Françoise Vimeux ◽  
Jean Jouzel ◽  
Vin Morgan ◽  
Marc Delmotte ◽  
...  
Keyword(s):  
Time Trend ◽  
Ross Sea ◽  
Ice Core ◽  
Ice Cores ◽  
West Antarctica ◽  
Climatic Fluctuations ◽  
Long Time ◽  
Long Term Trends ◽  
Isotopic Records

A comparison is made of the Holocene records obtained from water isotope measurements along 11 ice cores from coastal and central sites in east Antarctica (Vostok, Dome B, Plateau Remote, Komsomolskaia, Dome C, Taylor Dome, Dominion Range, D47, KM105, and Law Dome) and west Antarctica (Byrd), with temporal resolution from 20 to 50 yr. The long-term trends possibly reflect local ice sheet elevation fluctuations superimposed on common climatic fluctuations. All the records confirm the widespread Antarctic early Holocene optimum between 11,500 and 9000 yr; in the Ross Sea sector, a secondary optimum is identified between 7000 and 5000 yr, whereas all eastern Antarctic sites show a late optimum between 6000 and 3000 yr. Superimposed on the long time trend, all the records exhibit 9 aperiodic millennial-scale oscillations. Climatic optima show a reduced pacing between warm events (typically 800 yr), whereas cooler periods are associated with less-frequent warm events (pacing >1200 yr).

scholarly journals A new method to detect long term trends of methane (CH<sub>4</sub>) and nitrous oxide (N<sub>2</sub>O) total columns measured within the NDACC ground-based high resolution solar FTIR network

2011 ◽  
Vol 11 (13) ◽  
pp. 6167-6183 ◽  
Author(s):  
J. Angelbratt ◽  
J. Mellqvist ◽  
T. Blumenstock ◽  
T. Borsdorff ◽  
S. Brohede ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Regression Model ◽  
Multiple Regression ◽  
Atmospheric Chemistry ◽  
Multiple Regression Model ◽  
Long Term Trends ◽  
E 600 ◽  
Ch4 And N2o ◽  
Bootstrap Algorithm ◽  
Linear Trends

Abstract. Total columns measured with the ground-based solar FTIR technique are highly variable in time due to atmospheric chemistry and dynamics in the atmosphere above the measurement station. In this paper, a multiple regression model with anomalies of air pressure, total columns of hydrogen fluoride (HF) and carbon monoxide (CO) and tropopause height are used to reduce the variability in the methane (CH4) and nitrous oxide (N2O) total columns to estimate reliable linear trends with as small uncertainties as possible. The method is developed at the Harestua station (60° N, 11° E, 600 m a.s.l.) and used on three other European FTIR stations, i.e. Jungfraujoch (47° N, 8° E, 3600 m a.s.l.), Zugspitze (47° N, 11° E, 3000 m a.s.l.), and Kiruna (68° N, 20° E, 400 m a.s.l.). Linear CH4 trends between 0.13 ± 0.01-0.25 ± 0.02 % yr−1 were estimated for all stations in the 1996-2009 period. A piecewise model with three separate linear trends, connected at change points, was used to estimate the short term fluctuations in the CH4 total columns. This model shows a growth in 1996–1999 followed by a period of steady state until 2007. From 2007 until 2009 the atmospheric CH4 amount increases between 0.57 ± 0.22–1.15 ± 0.17 % yr−1. Linear N2O trends between 0.19 ± 0.01–0.40 ± 0.02 % yr−1 were estimated for all stations in the 1996-2007 period, here with the strongest trend at Harestua and Kiruna and the lowest at the Alp stations. From the N2O total columns crude tropospheric and stratospheric partial columns were derived, indicating that the observed difference in the N2O trends between the FTIR sites is of stratospheric origin. This agrees well with the N2O measurements by the SMR instrument onboard the Odin satellite showing the highest trends at Harestua, 0.98 ± 0.28 % yr−1, and considerably smaller trends at lower latitudes, 0.27 ± 0.25 % yr−1. The multiple regression model was compared with two other trend methods, the ordinary linear regression and a Bootstrap algorithm. The multiple regression model estimated CH4 and N2O trends that differed up to 31 % compared to the other two methods and had uncertainties that were up to 300 % lower. Since the multiple regression method were carefully validated this stresses the importance to account for variability in the total columns when estimating trend from solar FTIR data.

Effects of long-term fertilization on the yield of winter wheat and N forms on Luvic Phaeosem soil determined in 0.01 M CaCl 2

2010 ◽  
Vol 59 (1) ◽  
pp. 135-144 ◽  
Author(s):  
E. Bertáné Szabó ◽  
J. Loch ◽  
Gy. Zsigrai ◽  
L. Blaskó
Keyword(s):  
Winter Wheat ◽  
Wheat Yield ◽  
N Fertilization ◽  
N Balance ◽  
P Fertilization ◽  
Yield Data ◽  
Yield Increase ◽  
Winter Wheat Yield ◽  
Fertilization Practice

The effects of regular NPK fertilization on the amounts of winter wheat yield and the amounts and proportion of different N forms (NO 3 -N, NH 4 -N, N org , N total ) of a Luvic Phaeosem soil determined in 0.01 M CaCl 2 were studied in the B1740 variant of the National Long-Term Fertilization Experiment at Karcag. According to the yield data, N and P fertilization increased winter wheat yield significantly. When applying the 200 kg N·ha -1 dose, P fertilization resulted in a more than 2 t·ha -1 yield increase, as compared to the treatments without P fertilization. K fertilization had no effect on the yield, similarly to preceding years. These findings may be adapted to fields of the Middle-Tisza Region with similar conditions to the trial site. The N forms of the soil determined in CaCl 2 reflected fertilization well. All of the fractions, but especially NO 3 -N and N total , increased significantly in response to N fertilization. Close relationships (r = 0.87–0.88) were found among the NO 3 -N and N total fractions and the N balance, which means that the amounts of NO 3 -N and N total are suitable for assessing both the N deficit and the N surplus. The strength of the correlation between the NH 4 -N content and N balance was moderate (r = 0.65). The N org fraction increased significantly as a function of N and P fertilization. These results can be explained with the yield increase. A significant correlation (r = 0.55) was found between the N org fraction and yield amounts. It can be established that organic residuals remaining on the site resulted in a significant increase in the N org content of soils. The gained results confirm that the N org fraction is suitable for the characterization of the readily mobilizable N reserves previously ignored in fertilization practice. On the basis of the presented results the CaCl 2 method is recommended for the precise estimation of nutrient requirements.

scholarly journals The influence of mineral fertilisers, farmyard manure, liming and sowing rate on winter wheat grain yields

2018 ◽  
Vol 64 (No. 1) ◽  
pp. 38-46 ◽  
Author(s):  
Madaras Mikuláš ◽  
Mayerová Markéta ◽  
Kumhálová Jitka ◽  
Lipavský Jan
Keyword(s):  
Winter Wheat ◽  
Farmyard Manure ◽  
Climatic Conditions ◽  
Soil Conditions ◽  
Wheat Grain ◽  
Response Curves ◽  
Grain Yields ◽  
Yield Increase ◽  
Yield Trends

The influence of mineral fertilisers, liming, farmyard manure and sowing rate on the winter wheat grain yields was studied in a long-term field experiment at 4 sites under different soil and climatic conditions in the Czech Republic. A total of 135 partial fraction-factorial experiments were performed between 1980 and 2013 and evaluated using a statistical model with linear and quadratic terms for each factor. Yield trends demonstrated remarkable influence of fertilisation at two sites of lower starting productivity. Here, grain yields increased by 50% and 25% since the trial commencement, while the rate of yield increase was low at more productive sites. Yields were the most frequently influenced by nitrogen (N) fertilisation, uniformly at all sites. N response curves were strongly curvilinear, but these differed between sites and were affected by preceding crops. The relative frequency of statistically significant influences decreased in the following order: N (significant at α &lt; 0.05 in 89% of all partial trials) &gt; sowing rate (29%) &gt; phosphorus (22%) &gt; farmyard manure (15%) &gt; potassium (12%) &gt; liming (8%). This order and the frequencies of these influences are discussed with regard to relevant site and soil conditions.

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