Effect of shelter on the yield and water use of wheat

2002 ◽  
Vol 42 (6) ◽  
pp. 773 ◽  
Author(s):  
I. K. Nuberg ◽  
S. J. Mylius

Wheat was grown in the field and lysimeters under 3 experimental regimes — full exposure to wind, full shelter within an enclosure, and partial shelter behind an artificial windbreak — to test the hypothesis that a crop in a sheltered environment will be more conservative in its water use and more efficient in using that water to grow biomass. The fully sheltered wheat crop in the field produced 11% more above-ground biomass than the exposed crop and most of this difference was attributed to leaf (20%) and stem (21%) material. However, the sheltered crop had lower 1000-grain weights (35.6 g cf. 40.1 g) and higher protein (14.3% cf. 11.5%). No significant difference between sheltered and exposed yields could be confidently detected.Plants grown under non-water limiting conditions of lysimeters produced 14% more biomass under shelter and were also likely to be more efficient (7%, P = 0.06) in their use of water to produce that biomass than wind-exposed plants. Shelter did not change the total soil water use of the lysimeter- or field-grown wheat. However, the sheltered field crop was more conservative than the exposed crop in its use of soil water up to anthesis and less conservative during grain filling. In the partial shelter regime wheat was grown in the ground and in lysimeters at distances of 3�H (i.e. 3 × windbreak height), 6 H, 12 H, 15 H, 18 H and 24 H from an artificial windbreak. Significant relationships with distance from this windbreak were only observed in total biomass, stem weight and head weight of field-grown wheat at anthesis. In summary, the sheltered wheat was more efficient in production of biomass and did conserve water early in the growing season but the conserved soil water was expended to maintain that biomass at the expense of grain size.

2005 ◽  
Vol 56 (7) ◽  
pp. 743 ◽  
Author(s):  
Heping Zhang ◽  
Neil C. Turner ◽  
Michael L. Poole

Water use of wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), canola (Brassica napus L.), and lucerne (Medicago sativa L.) was measured on a duplex soil in the high rainfall zone (HRZ) of south-western Australia from 2001 to 2003. Rainfall exceeded evapotranspiration in all years, resulting in transient perched watertables, subsurface waterlogging in 2002 and 2003, and loss of water by deep drainage and lateral flow in all years. There was no significant difference in water use among wheat, barley, and canola. Lucerne used water at a similar rate to annual crops during the winter and spring, but continued to extract 80−100 mm more water than the annual crops over the summer and autumn fallow period. This resulted in about 50 mm less drainage past the root-zone than for annual crops in the second and third years after the establishment of the lucerne. Crop water use was fully met by rainfall from sowing to anthesis and a significant amount of water (120−220 mm) was used during the post-anthesis period, resulting in a ratio of pre- to post-anthesis water use (ETa : ETpa) of 1 : 1 to 2 : 1. These ratios were lower than the indicative value of 2 : 1 for limited water supply for grain filling. High water use during the post-anthesis period was attributed to high available soil water at anthesis, a large rooting depth (≥1.4 m), a high proportion (15%) of roots in the clay subsoil, and regular rainfall during grain filling. The pattern of seasonal water use by crops suggested that high dry matter at anthesis did not prematurely exhaust soil water for grain filling and that it is unlikely to affect dry matter accumulation during grain filling and final grain yield under these conditions.


2018 ◽  
Vol 156 (5) ◽  
pp. 628-644 ◽  
Author(s):  
E. Pohanková ◽  
P. Hlavinka ◽  
M. Orság ◽  
J. Takáč ◽  
K. C. Kersebaum ◽  
...  

AbstractIn the current study, simulations by five crop models (WOFOST, CERES-Barley, HERMES, DAISY and AQUACROP) were compared for 7–12 growing seasons of spring barley (Hordeum vulgare) at three sites in the Czech Republic. The aims were to compare how various process-based crop models with different calculation approaches simulate different values of transpiration (Ta) and evapotranspiration (ET) based on the same input data and compare the outputs of these simulations with reference data. From the outputs of each model, the water use efficiency (WUE) from Ta (WUETa) and from actual ET (WUEETa) was calculated for grain yields and above-ground biomass yield. The results of the first part of the study show that the model with the Penman approach for calculating ET simulates lower actual ET (ETa) sums, at an average of 250 mm during the growing season, than other models, which use the Penman–Monteith approach and simulate 330 mm on average during the growing season. In the second part of the current study, WUE reference values in the range 1.9–2.4 kg/m3were calculated for spring barley and grain yield. Values of WUETa/WUEETacalculated from the outputs of individual models for grain yields and above-ground biomass yields ranged from 2.0/1.0 to 5.9/3.8 kg/m3with an average value of 3.2/2.0 kg/m3and from 3.9/2.1 to 10.5/6.8 kg/m3with an average value of 6.5/4.0 kg/m3, respectively. The results confirm that the average values of all models are nearest to actual values.


1978 ◽  
Vol 91 (3) ◽  
pp. 599-623 ◽  
Author(s):  
W. Day ◽  
B. J. Legg ◽  
B. K. French ◽  
A. E. Johnston ◽  
D. W. Lawlor ◽  
...  

SummaryAutomatic mobile shelters were used to keep rain off a barley crop in a drought experiment. The treatments ranged from no water during the growing season to regular weekly irrigation. This paper reports the effect of drought on the harvest yield and its components, on water use and nutrient uptake.Drought caused large decreases in yield, and affected each component of the grain yield. The magnitude of each component varied by up to 25% between treatments, and much of the variation could be accounted for by linear regression against the mean soil water deficit in one of three periods. For the number of grains per ear, the relevant period included tillering and ear formation; for the number of ears per unit ground area, the period included stem extension and tiller death; for grain mass, the period included grain filling.The harvest yields were linearly related to water use, with no indication of a critical period of drought sensitivity. The relation of grain yield to the maximum potential soil water deficit did show that a prolonged early drought had an exceptionally large effect on both yield and water use.Two unsheltered irrigation experiments, also on barley, were made in the same year on a nearby site. The effects of drought on yield in these experiments were in good agreement with the effects observed on the mobile shelter site.When fully irrigated, the small plots under the mobile shelters used water 11% faster than larger areas of crop, because of advection. The maximum depth from which water was extracted was unaffected by the drought treatment. When 50% of the available soil water had been used the uptake rate decreased, but the maximum depth of uptake continued to increase.Measurements of crop nutrients at harvest showed that nitrogen uptake was large, because of site history, and that phosphate uptake was decreased by drought to such an extent that phosphate shortage may have limited yield.


2007 ◽  
Vol 87 (2) ◽  
pp. 289-292 ◽  
Author(s):  
H. Wang ◽  
T. N. McCaig ◽  
R. M. DePauw ◽  
J. M. Clarke ◽  
R. Lemke

Recently developed cultivars of Canada Western Red Spring (CWRS) wheat (Triticum aestivum L.) and Canada Western Amber Durum (CWAD) (Triticum turgidum L. var durum) produced significantly more grain than older cultivars. This production was attributed to higher harvest indices and better water use efficiency. Durum cultivars and CWRS AC Intrepid and AC Barrie extracted relatively more soil water below 55 cm, which may be advantageous in minimizing leaching and related to drought tolerance during grain-filling. Key words: Hexaploid wheat, durum, water use, soil water


2017 ◽  
Vol 35 (1) ◽  
pp. 68-74 ◽  
Author(s):  
Javier García A. ◽  
Gerhard Fischer ◽  
Nestor Riaño H.

The effect of the amount of fertilization applied to the corn variety 'ICA V-156' (white grain) was calibrated and validated with the simulator AquaCrop in Cerete (Cordoba, Colombia) at an altitude of 20 m. The fertilization level determined factors related to biomass production, the harvest index, yield and water use, and potential evapotranspiration (Eto). The basic information which calibrated and validated the model came from research conducted in different altitudes in maize growing areas in Colombia. Unexpectedly, the water shortages occurred during the growing season, which the modelling had not considered. Levels of 90 to 60% of fertilization were applied to the crop according to the analysis of the evaluated soil. The information was subjected to an analysis of variance; the results showed that the level of fertilization affected the formation of biomass, harvest index and yield, as well as, the use of water during the growing season. The ETo values were extreme at 0.9 and 7.3 mm day-1. Likewise the total biomass production was 4.64% less at the level of 90 and 25.04% less at 60% fertilization, as compared to the biomass measurements in the field. Similarly, the harvest index was 32.3 and 29.8% for the 90 and 60% levels of fertilization, respectively; on the other hand the grain yield was not affected by the highest level (90%), whereas when the reduction in fertilization was 40%, a decrease of 14.335% in the grain yield was obtained. In addition, per m3 of water 18.87 and 23.02 kg of grain for the fertilization levels of 60 and 90% were formed, respectively.


1999 ◽  
Vol 79 (1) ◽  
pp. 11-17 ◽  
Author(s):  
S. A. Brandt

Previous research with lentil (Lens culinaris Medic.) green manure in the semiarid prairies of western Canada has indicated that water use by the green manure crop often reduces grain yield of the succeeding cereal crop compared to those obtained after conventional summerfallow. In this study, we evaluated several green manure management practices that have potential to trap snow and enhance overwinter soil water recharge. These practices included: using herbicides to halt the growth of the green manure crop thus eliminating the need for soil incorporation, planting mustard (Sinapis alba L.) strips after incorporation, and leaving standing strips of non-incorporated lentil. Our results showed that none of the green manure management strategies increased wheat (Triticum aestivum L.) yield or grain protein concentration compared to wheat grown on conventional summerfallow. Leaving strips of standing lentil during bud stage incorporation provided barriers for wind erosion protection, while not decreasing wheat yield or protein content. Glyphosate or 2,4-D amine applied at bud stage of the lentil, and without soil incorporation, reduced available soil N. However, 2,4-D did not halt plant growth and water use quickly enough to avoid reducing yield of the succeeding wheat crop, while glyphosate generally halted water use more rapidly. The inability of the green manure management strategies to increase wheat yields over that obtained from conventional summerfallow was because the soil rooting zone is typically filled to capacity with water by this latter practice under the prevailing soil and climatic conditions. If green manuring is practised, early incorporation with lentil leave strips is the most promising management system. However, even with improved water management practices, green manuring did not demonstrate a consistent advantage over summerfallow, which may be required to offset the added economic costs required to enact this practice. Key words: Lens culinaris, legumes, summerfallow, soil nitrogen, soil water, wheat


2013 ◽  
Vol 404 ◽  
pp. 415-419
Author(s):  
Heng Jia Zhang ◽  
Jun Hui Li

The soil water contents in spring maize field were monitored continuously using soil neutron probe combined with drying-weighing method. Meanwhile, the effect of limited irrigation on crop periodic water consumption and its percentage in total water use, leaf area index, and grain yield of spring maize were explored. The results indicated that both the periodic water consumption and its percentage in total water use varied from low to high then to low within maize growing season, with the maximum valued both at silking to middle grain filling. In addition, leaf area indexes were greatly improved by full irrigation before maize filling, and grain yield was not reduced by efficient limited irrigation management, contrarily, yield increase and 31.1% of significant irrigation water saving were achieved, which was beneficial to the optimization of soil water ecological processing and limited irrigation management.


1980 ◽  
Vol 31 (5) ◽  
pp. 873 ◽  
Author(s):  
JF Angus ◽  
HA Nix ◽  
JS Russell ◽  
JE Kruizinga

Wheat crops in southern Queensland grown on two different clay soils were studied in terms of growth, development, water economy, and uptake of nitrogen and phosphorus in a season when growing season rainfall was only 50 mm. No significant grain yield response to either nitrogen or phosphorus was detected, although growth response in the vegetative phase was apparent. Mean grain yields on the two soils were 254 and 277 g m-2. These are underestimates of yield potential because of losses due to a mouse plague. Mean yield inside metal mouse exclosures was 303 g m-2. On the higher-yielding site the water use determined from augered soil samples was 192 mm, comprising 50 mm of rain during the 139 days of crop growth and 142 mm of soil water conserved during the preceding summer. The pattern of water extraction was sequential removal of the stored water, starting from the soil surface and extending to a depth below 90 cm. Soil water potential after flowering reached well below - 15 bars. The water use efficiency for grain production was 1.58 g m-2 mm-1 of evapotranspiration, which is higher than most other reports for wheat crops found in the literature. A partial explanation for this high value is that most of the soil water (est. 86%) was transpired by the crop with only a minor proportion (14 %) lost by bare soil evaporation. In addition, the crop appeared to become progressively more adapted to water stress from early in the life cycle, and this stress resulted in slow extraction of subsoil water held at low potentials and therefore in conservation of soil water until the grain-filling phase. The results are discussed by comparing them with those of a crop grown mostly on current rainfall.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
JAMES G. KAIRO ◽  
MICHAEL NJOROGE GITHAIGA ◽  
KIPLAGAT KOTUT ◽  
FRANCIS KARIUKI

Abstract. Githaiga MN, Kotut K, Kariuki F, Kairo JG. 2019. Structure and biomass accumulation of natural mangrove forest at Gazi Bay, Kenya. Bonorowo Wetlands 9: 18-32. The goal of this study was to determine the forest structure and estimate biomass accumulation above and below ground in the mangrove forest of Gazi Bay. The western, middle, and eastern forest blocks of the Gazi Bay mangrove forest were investigated for forest structure, whereas the western forest block was determined for biomass accumulation. To calculate below-ground biomass accumulation, in-growth cores of 80 cm long, 20 cm broad, and 60 cm deep were employed. Above-ground biomass accumulation was calculated using data on tree height and stem diameter at breast height (DBH-130). Leaf phenology was observed by tagging shoots. At the start, environmental variables were measured every four months for a year across four mangrove species zones. The linear regeneration sampling approach was used to determine the composition and distribution pattern of natural regeneration (LRS). Salinity revealed a strong negative connection with above-ground biomass accumulation among the soil environment characteristics studied. Sonneratia alba had the highest biomass accretion rate of 10.5 1.9 t ha-1 yr-1 among the four forest zones. Rhizophora mucronata (8.5 0.8 t ha-1 yr-1), Avicennia marina (5.2 1.8 t ha-1 yr-1), and Ceriops tagal (2.6 1.5 t ha-1 yr-1) were the next most abundant species. Above-ground and below-ground biomass accumulation differed significantly among zones (F (3, 8) = 5.42, p = 0.025) and (F (3, 8) = 16.03, p = 0 001), respectively. There was a significant difference in total biomass accumulation across zones (F (3, 8) =15.56, p = 0.001). For the entire forest, a root : shoot biomass accumulation ratio of 2 : 5 was calculated. This study's findings provide more accurate estimates of mangrove carbon capture and storage, which can be used in carbon credit discussions in the emerging carbon market.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8738 ◽  
Author(s):  
Jiao Ning ◽  
Xiong Z. He ◽  
Fujiang Hou ◽  
Shanning Lou ◽  
Xianjiang Chen ◽  
...  

Alfalfa in China is mostly planted in the semi-arid or arid Northwest inland regions due to its ability to take up water from deep in the soil and to fix atmospheric N2 which reduces N fertilizer application. However, perennial alfalfa may deplete soil water due to uptake and thus aggravate soil desiccation. The objectives of this study were (1) to determine the alfalfa forage yield, soil property (soil temperature (ST), soil water content (SWC), soil organic carbon (SOC) and soil total nitrogen (STN)) and greenhouse gas (GHG: methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2)) emissions affected by alfalfa stand age and growing season, (2) to investigate the effects of soil property on GHG emissions, and (3) to optimize the alfalfa stand age by integrating the two standard criteria, the forage yield and water use efficiency, and the total GHG efflux (CO2-eq). This study was performed in alfalfa fields of different ages (2, 3, 5 and 7 year old) during the growing season (from April to October) in a typical salinized meadow with temperate continental arid climate in the Northwest inland regions, China. Despite its higher total GHG efflux (CO2-eq), the greater forage yield and water use efficiency with lower GEIhay and high CH4 uptake in the 5-year alfalfa stand suggested an optimal alfalfa stand age of 5 years. Results show that ST, SOC and RBM alone had positive effects (except RBM had no significant effect on CH4 effluxes), but SWC and STN alone had negative effects on GHG fluxes. Furthermore, results demonstrate that in arid regions SWC superseded ST, SOC, STN and RBM as a key factor regulating GHG fluxes, and soil water stress may have led to a net uptake of CH4 by soils and a reduction of N2O and CO2 effluxes from alfalfa fields. Our study has provided insights into the determination of alfalfa stand age and the understanding of mechanisms regulating GHG fluxes in alfalfa fields in the continental arid regions. This knowledge is essential to decide the alfalfa retention time by considering the hay yield, water use efficiency as well as GHG emission.


Sign in / Sign up

Export Citation Format

Share Document