OPTIMIZING TIME DISTRIBUTION OF WATER SUPPLY AND FERTILIZER NITROGEN RATES IN RELATION TO TARGETED WHEAT YIELDS

2000 ◽  
Vol 36 (1) ◽  
pp. 115-125 ◽  
Author(s):  
K. S. SANDHU ◽  
V. K. ARORA ◽  
RAMESH CHAND ◽  
B. S. SANDHU ◽  
K. L. KHERA
Keyword(s):  
Water Supply ◽  
Grain Yield ◽  
Field Experiments ◽  
Sandy Loam ◽  
Crop Growth ◽  
Fertilizer N ◽  
Fertilizer Nitrogen ◽  
Efficient Resource ◽  
Nitrogen Rates

Long-term field experiments were conducted at six different sites (representing dryland and irrigated environments) with wheat (Triticum aestivum) on sandy loam soils to generate a database relating available water supply and fertilizer nitrogen (N) rate to grain yield. Step-wise multiple regression analysis showed that water supply and fertilizer N at more than 53 cm a−1 and 103 kg ha−1 a−1 were unproductive. A method, based on the principle of equi-marginal productivity of water in different periods of crop growth, has been used to estimate the optimum allocation of the variable amounts of water supply over the growing season. The optimized quantities of water in different periods of crop growth were then employed to compute fertilizer N requirement to achieve a given yield target. For medium grain yield targets (4–5 t ha−1), the range of substitution between fertilizer N and water for efficient resource use was quite wide.

MAGNITUDE AND ECONOMICS OF FERTILIZER NITROGEN RESPONSE OF WHEAT IN RELATION TO AMOUNT AND TIMING OF WATER INPUTS

2002 ◽  
Vol 38 (1) ◽  
pp. 65-78 ◽  
Author(s):  
K. S. Sandhu ◽  
V. K. Arora ◽  
Ramesh Chand
Keyword(s):  
Water Supply ◽  
Grain Yield ◽  
Capital Investment ◽  
Wheat Yield ◽  
Fertilizer N ◽  
Nitrogen Response ◽  
Fertilizer Nitrogen ◽  
Available Water ◽  
Irrigation Regimes ◽  
Input Prices

Long-term data (20 years) on wheat (Triticum aestivum) grain yield under various fertilizer-nitrogen (N) and water conditions in rainfed and irrigated environments of sub-tropical north India were used to assess the magnitude and economics of N response in relation to amount and timing of irrigation. Treatments comprised combinations of fertilizer N rates (ranging from 0 to 150 kg ha−1) and irrigation regimes (rainfed, supplemental, limited, and adequately irrigated). Regression analysis of wheat yield against available water supply and fertilizer N showed a strong interaction between the two variables for grain yield and input use efficiency. The effect, on grain yield and returns, of increasing the N rate for a given water supply was influenced by the irrigation regimes. Economic optimization of water and N, based on constrained profit maximization technique, showed that optimum amounts of available water (or irrigation) and fertilizer N are related directly to the capital investment. Increased input prices lowered their optimum levels for a given investment. The analysis suggests an approach for resource allocation that relates to capital investment and input prices.

Grain yield and crop N offtake in response to residual fertilizer N in long-term field experiments

2010 ◽  
Vol 26 (4) ◽  
pp. 455-464 ◽  
Author(s):  
J. Petersen ◽  
I. K. Thomsen ◽  
L. Mattsson ◽  
E. M. Hansen ◽  
B. T. Christensen
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Fertilizer N ◽  
Residual Fertilizer N ◽  
Term Field

scholarly journals Pre-Anthesis Nutritional Status of Spelt Wheat as a Tool for Predicting the Attainable Grain Yield

Agronomy ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 558
Author(s):  
Witold Grzebisz ◽  
Przemysław Barłóg ◽  
Jan Kryszak ◽  
Remigiusz Łukowiak
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Nutrient Content ◽  
Thousand Grain Weight ◽  
Reliable Prediction ◽  
Spelt Wheat ◽  
Nutritional Factor ◽  
Supply Potential ◽  
Term Field

The nutrient content in leaves of spelt wheat at late heading is crucial for the development of its yield components, and in consequence, grain yield. This hypothesis was verified based on data from long-term field experiments with four potassium (K) treatments based on the progressive K supply potential to plants from soil and fertilizer and two magnesium treatments (−Mg, +Mg). The number of ears (NE) and the number of grains per ear (NGE) responded significantly to the increased K and Mg supply. The grain yield was positively correlated with NGE. A shortage of N and Mg resulted in a lower NGE, whereas a shortage of N and Zn, concomitant with an excess of Ca, resulted in a significant decrease in NGE and thousand-grain weight. This effect can be diminished by the increased content of Mg. It has been revealed that the content of Zn in leaves of spelt wheat at heading is an important nutritional factor effectively controlling N, P and Fe contents in grain, and consequently, grain yield. This study showed that the content of nutrients in spelt leaves measured just before anthesis can be used for reliable prediction of the grain yield.

scholarly journals Drought response of modern and old oat lines in greenhouse and long-term field trials

1997 ◽  
Vol 6 (2) ◽  
pp. 199-205 ◽  
Author(s):  
Pirjo Mäkelä ◽  
Leena Väärälä ◽  
Riikka Rajalahti ◽  
Ari Rajala ◽  
Pirjo Peltonen-Sainio
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Field Trials ◽  
Drought Response ◽  
Wild Oat ◽  
Greenhouse Experiments ◽  
Plant Breeding Institute ◽  
The University ◽  
Term Field

This study compares the response of old and modern oat (Avena sutiva L.) lines to pre-anthesis precipitation in long-term field trials, and to pre- and post-anthesis drought in the greenhouse. Long-term field trials were carried out at the Experimental Farms of Hankkija Plant Breeding Institute and the University of Helsinki between 1965 and 1988. Grain yield of 12 oat lines (released since 1959) was compared with that of the check lines. The effect of differences in May-June precipitation on grain yield was established for different lines. Greenhouse experiments included 19 oat lines (released since 1921) and three wild species of oat (A. barbata L., A. sterilis max. L. and A. fatua L.). The data from greenhouse experiments were analysed using discriminant analysis in groups of old (released before 1970s), modern, and wild oat types. Ranking of the oat lines according to results from long-term field trials and greenhouse experiments was not consistent; contrary to the field experiments, the old lines tended to be the most drought sensitive when tested in the greenhouse. Therefore, the simple and non-laborious methods used in this study for ranking of drought sensitivity of oat lines are not recommended.

Fixed-time corrective dose fertilizer nitrogen management in wheat using atLeaf meter and leaf colour chart

2021 ◽  
pp. 1-12
Author(s):  
Ali M. Ali ◽  
Sherif M. Ibrahim ◽  
Wahby M. Hassany ◽  
Ashraf N. El-Sadek ◽  
Bijay-Singh
Keyword(s):  
Grain Yield ◽  
Growth Stage ◽  
Standard Treatment ◽  
Management Strategies ◽  
Test Plot ◽  
Fertilizer N ◽  
Fertilizer Nitrogen ◽  
Leaf Colour ◽  
N Management ◽  
Colour Chart

Abstract Fertilizer nitrogen (N) management in any region following standard general recommendations discount the fact that crop response to N varies between sites and seasons. To devise field-specific N management in wheat at jointing stage (Feekes 6 growth stage) using atLeaf meter and leaf colour chart (LCC), eight field experiments were conducted in three wheat seasons during 2017–2020 in the West Delta of Egypt. In the first two seasons, four experiments consisted of treatments with a range of fertilizer N application levels from 0 to 320 kg N ha−1. Monitoring atLeaf and LCC measurements at Feekes 6 growth stage in plots with different yield potentials allowed formulation of different criteria to apply field-specific and crop need-based fertilizer N doses. In the four experiments conducted in the third season in 2019/20, different field-specific N management strategies formulated in 2017/18 and 2018/19 wheat seasons were evaluated. In the atLeaf-based fertilizer N management experiment, prescriptive application of 40 kg N ha−1 at 10 days after seeding (DAS) and 60 kg N ha−1 at 30 DAS followed by application of an adjustable dose at Feekes 6 stage computed by multiplying the difference of atLeaf measurements of the test plot and the N-sufficient plot with 42.25 (as derived from the functional model developed in this study), resulted in grain yield similar or higher to that obtained by following the standard treatment. The LCC-based strategy to apply field-specific fertilizer N at Feekes 6 stage consisted of applying 150, 100 or 0 kg N ha−1 based on LCC shade equal to or less than 4, between 4 and 5 or equal to or more than 5, respectively. Both atLeaf- and LCC-based fertilizer N management strategies not only recorded the highest grain yield levels but also resulted in higher use efficiency with 57–60 kg N ha−1 in average less fertilizer use than the standard treatment.

Rate and time of fertilizer nitrogen application on yield, protein and apparent efficiency of fertilizer nitrogen use of spring wheat

2007 ◽  
Vol 87 (4) ◽  
pp. 709-718 ◽  
Author(s):  
B. J. Zebarth ◽  
E. J. Botha ◽  
H. Rees
Keyword(s):  
Triticum Aestivum ◽  
Grain Yield ◽  
Spring Wheat ◽  
N Mineralization ◽  
Grain Protein ◽  
Soil N ◽  
Fertilizer N ◽  
N Application ◽  
Fertilizer Nitrogen ◽  
N Status

Use of an in-season measurement of crop nitrogen (N) status to optimize fertilizer N management has been proposed as a means of optimizing yield of spring wheat while minimizing environmental N losses. This study determined the effect of the rate and time of fertilizer N application on the grain yield, grain protein, and apparent recovery of fertilizer N in grain and in the above-ground plant for spring wheat (Triticum aestivum L.) in 2001–2003, and evaluated the use of a SPAD-502 meter to measure crop N status in spring wheat. Sixteen N fertility treatments were used, including application of different rates of fertilizer N (0–160 kg N ha-1) applied pre-seeding (ZGS 0), at tillering (ZGS 21) and at shooting (ZGS 32) as ammonium nitrate. Split N application provided no benefit in terms of grain yield or apparent recovery of fertilizer N. Application of fertilizer N at ZGS 32 reduced crop yield and apparent recovery of fertilizer N compared with N application at ZGS 0. Application of fertilizer N at ZGS 21 reduced yield and apparent recovery of fertilizer N in grain in 2 of 3 yr, but had no effect on apparent recovery of fertilizer N in the above-ground plant. Delayed fertilizer N application generally increased grain protein. Fertilizer N can be applied at ZGS 21 as required to optimize grain yield provided at least some fertilizer N is applied prior to seeding; however, crop N status cannot reliably be assessed at this time using a SPAD-502 meter. Crop N status can be assessed at ZGS 32 using a SPAD-502 meter; however, fertilizer N application at this time primarily influences grain protein rather than grain yield. These results highlight the need for a means of predicting soil N mineralization potential in order to optimize grain yield in humid environments where carry-over of soil nitrate from the previous growing season is limited. Key words: Triticum aestivum; N mineralization; soil N supply; SPAD-502 meter, leaf chlorophyll index

EFFETS DES TEMPERATURES DU SOL, DES DATES DE SEMIS ET DES MAUVAISES HERBES SUR LES COMPOSANTES DU RENDEMENT DE L’AVOINE

1980 ◽  
Vol 60 (1) ◽  
pp. 61-68 ◽  
Author(s):  
J. M. DESCHENES ◽  
C. A. ST-PIERRE
Keyword(s):  
Soil Temperature ◽  
Grain Yield ◽  
Field Experiments ◽  
Sandy Loam ◽  
Dry Weight ◽  
Soil Types ◽  
Grain Yields ◽  
Soil Temperatures ◽  
Weed Infestation ◽  
Hand Weeding

On a St-André sandy loam and on a Kamouraska clay, the effect of soil temperature on oats (Avena sativa L.) was measured in the greenhouse using a system described by Deschênes et al. in 1974 and in the field, using two dates of seeding. The effect of weeds was measured by using un weeded and hand-weeded treatments. In the greenhouse, cool soil temperatures have delayed maturity and decreased straw and grain yields as well as total phytomass of oats on the two soil types. The dry weight of weeds in un weeded pots increased slightly. The effect of hand-weeding on oats was especially noticeable on the St-André sandy loam where three times as many weeds were observed. The straw yield and the total phytomass of oats were higher in the field experiment following an early seeding of oats on both soil types. On the other hand, grain yield was lower on plots seeded early and located on St-André sandy loam while the opposite was true on Kamouraska clay. The dry weight of weeds was lower on unweeded plots seeded early. The weeds reduced straw and grain yields on the St-André sandy loam but had no effect on Kamouraska clay because of the low weed infestation on the latter. The greenhouse and field experiments suggest that soil temperature is not the main factor in explaining the increase in grain yield observed with early-seeded cereals.

scholarly journals Using a Portable Active Sensor to Monitor Growth Parameters and Predict Grain Yield of Winter Wheat

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1108 ◽  
Author(s):  
Jiayi Zhang ◽  
Xia Liu ◽  
Yan Liang ◽  
Qiang Cao ◽  
Yongchao Tian ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Vegetation Index ◽  
Field Experiments ◽  
Growth Parameters ◽  
Leaf Nitrogen ◽  
Crop Growth ◽  
Nitrogen Accumulation ◽  
Wheat Cultivars ◽  
Area Index

Rapid and effective acquisition of crop growth information is a crucial step of precision agriculture for making in-season management decisions. Active canopy sensor GreenSeeker (Trimble Navigation Limited, Sunnyvale, CA, USA) is a portable device commonly used for non-destructively obtaining crop growth information. This study intended to expand the applicability of GreenSeeker in monitoring growth status and predicting grain yield of winter wheat (Triticum aestivum L.). Four field experiments with multiple wheat cultivars and N treatments were conducted during 2013–2015 for obtaining canopy normalized difference vegetation index (NDVI) and ratio vegetation index (RVI) synchronized with four agronomic parameters: leaf area index (LAI), leaf dry matter (LDM), leaf nitrogen concentration (LNC), and leaf nitrogen accumulation (LNA). Duration models based on NDVI and RVI were developed to monitor these parameters, which indicated that NDVI and RVI explained 80%, 68–70%, 10–12%, and 67–73% of the variability in LAI, LDM, LNC and LNA, respectively. According to the validation results, the relative root mean square error (RRMSE) were all <0.24 and the relative error (RE) were all <23%. Considering the variation among different wheat cultivars, the newly normalized vegetation indices rNDVI (NDVI vs. the NDVI for the highest N rate) and rRVI (RVI vs. the RVI for the highest N rate) were calculated to predict the relative grain yield (RY, the yield vs. the yield for the highest N rate). rNDVI and rRVI explained 77–85% of the variability in RY, the RRMSEs were both <0.13 and the REs were both <6.3%. The result demonstrates the feasibility of monitoring growth parameters and predicting grain yield of winter wheat with portable GreenSeeker sensor.

Effect of Supplementary Saline Irrigation and Applied Nitrogen on the Performance of Dryland Seeded Indian Mustard (Brassica juncea)

1995 ◽  
Vol 31 (4) ◽  
pp. 423-428 ◽  
Author(s):  
Bhu Dayal ◽  
P. S. Minhas ◽  
C. P. S. Chauhan ◽  
R. K. Gupta
Keyword(s):  
Field Experiments ◽  
Saline Water ◽  
Indian Mustard ◽  
Growth And Yield ◽  
Saline Irrigation ◽  
Nitrogen Use ◽  
Fertilizer Nitrogen ◽  
Nitrogen Levels ◽  
Nitrogen Rates ◽  
Seasonal Water Use

SUMMARYField experiments were conducted for two years to evaluate the effects of combinations of saline irrigation (ECw 14.0 ds m-1) and nitrogen levels on the yield, seasonal water use and nitrogen use efficiencies of mustard. These showed that the use of saline water can boost the growth and yield of dryland mustard and that, within certain limits, a non-saline water supply can be substituted by applying nitrogen and saline water. It is suggested that fertilizer nitrogen rates should be adjusted in relation to the supply of water and its predicted salinity.Irrigación salina y los efectos del nitrógeno en la mostaza sembrada en las tierras de secano

Ryegrass populations from intensively managed leys: II. Reaction to nitrogen and Poa trivialis L.

1971 ◽  
Vol 76 (2) ◽  
pp. 233-241 ◽  
Keyword(s):  
Dry Matter ◽  
Total Yield ◽  
Reverse Effect ◽  
Fertilizer N ◽  
N Application ◽  
Fertilizer Nitrogen ◽  
Poa Trivialis ◽  
The Difference ◽  
Intensively Managed ◽  
Nitrogen Rates

SUMMARYA Lolium perenne L. population derived from a very productive 6-year-old S.23 ley was compared with that obtained from breeders' seed of S.23. The ryegrasses wqre grown in boxes sown separately, together, and also with Poa trivialis L. Three rates of nitrogen were applied equivalent to 28, 336 and 672 kg N/ha.The results obtained when the two ryegrasses were sown separately differed from those obtained in mixtures. When sown alone, the difference between the two ryegrass populations was small, but the ‘survivor’ ryegrass had a slightly higher yield of dry matter and nitrogen at some sampling dates and fertilizer nitrogen rates. In the mixture of the two ryegrasses, S.23 was higher yielding than the ‘survivor’ population when the equivalent of 672 kg N/ha was applied, but not at lower nitrogen rates.When grown as pure swards, P. trivialis did not yield as much dry matter and nitrogen as L. perenne at the highest N application. In the intergeneric mixtures, the total yield of ryegrass × P. trivialis was not very different from that of ryegrass sown alone. P. trivialis depressed the yield of ryegrass in May and June, particularly when fertilizer N was applied; the reverse effect was recorded later in the year. Total drymatter yield of ryegrass and P. trivialis grown together was similar at the highest fertilizer N rate, but the yield of N was much higher in ryegrass than in P. trivialis.

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