Delving of sandy surfaced soils reduces frost damage in wheat crops

2007 ◽  
Vol 58 (2) ◽  
pp. 105 ◽  
Author(s):  
M. Rebbeck ◽  
C. Lynch ◽  
P. T. Hayman ◽  
V. O. Sadras

Delving is a farming practice involving the mixing of a deep clayey subsoil layer with a sandy topsoil. One of the many effects of this practice is to reduce soil albedo and increase water-holding capacity of the topsoil, thus increasing the potential for storage and release of heat and potential attenuation of the effects of radiative frost. At Keith, a frost-prone location of South Australia, we investigated the effect of management practices with putative capacity to reduce frost damage, with emphasis on delving. Three field experiments were established on Brown Sodosols with a water-repellent sand topsoil. In relation to crops in untreated control soil, delving increased wheat yield from 1.9 to 3.1 t/ha in 2003, and from 0.5 to 1.5 t/ha in 2004. This large delving effect contrasted with the minor effects of other treatments including soil rolling, sowing rate, row spacing, and cultivar mixture. Lack of significant interactions between treatments indicated a robust response to delving across a range of management practices. Topsoil and canopy-height minimum temperatures were consistently higher in the delved treatment. The average difference in canopy-height minimum temperature between delved and control treatments was 0.3–0.4°C, with a maximum of 1.6°C in 2003 and 1.2°C in 2004. A single, robust relationship between yield and frost damage fitted the data pooled across treatments and seasons. This, together with the temperature differential between treatments, and significant relationships between minimum canopy-height temperature around flowering and frost damage supported the conclusion that a substantial part of the yield gain attributable to delving was related to reduced frost damage.

Soil Research ◽  
1964 ◽  
Vol 2 (1) ◽  
pp. 123 ◽  
Author(s):  
RD Bond

The water repellence of sandy soils has been investigated at sites in the upper south-east of South Australia by observation of infiltration patterns and measurement of contact angle of wetting. Water penetrated into repellent sands through narrow channels, the intervening soil remaining dry. Such dry areas persisted through the winter months and were responsible for a mosaic pattern of bare and grassed areas in severely affected paddocks. The intensity of water repellence has been found to vary with species of plant cover, age of pasture, and also management practices.


1991 ◽  
Vol 42 (5) ◽  
pp. 875 ◽  
Author(s):  
SJ Carr ◽  
GSP Ritchie ◽  
WM Porter

Many of the yellow earths in the Western Australian wheatbelt have naturally acidic subsoils which can reduce the yield of wheat grown on them. Current methods of assessing soil acidity cannot identify which soils have subsoil acidity severe enough to restrict wheat yields. We conducted 53 field experiments at 34 sites in 5 regions over 3 years to determine the relationship between yield of wheat and several different indices for identifying subsoils with toxic concentrations of aluminium, Al. Initially, we identified that the concentration of aluminium, [All, in the soil solution and in 1 : 5 0.005 M KCl extracts of soil from the 15-25 cm layer was responsible for the majority of the decrease in wheat yield. The concentration of Al in a 1 : 5 0.005 M KCl extract in the 15-25 cm layer was well correlated with grain yield of wheat grown on yellow earth soils in the Merredin region, provided the soils had similar fertilizer treatments. The ratio [All : [Na] in a 1 : 5 0.005 M KCl extract was a better predictor than [All alone of grain yield of wheat grown on yellow earths in different regions and with different fertilizer practices. The three seasons had little effect on the correlation between yield and different soil indices. The correlations determined were strongly affected by regional differences, which were probably due to differing water supply and availability. The choice of toxicity index depended on the uniformity of fertilizer management practices within a region and it appeared that both ionic strength and calcium were important mitigating factors.


2019 ◽  
Vol 34 (1) ◽  
pp. 19-24
Author(s):  
David J. Brunton ◽  
Peter Boutsalis ◽  
Gurjeet Gill ◽  
Christopher Preston

AbstractTwo field experiments were conducted during 2018 at Paskeville and Arthurton, South Australia, to identify effective herbicide options for the control of thiocarbamate-resistant rigid ryegrass in wheat. Dose–response experiments confirmed resistance in both field populations (T1 and A18) of rigid ryegrass to triallate, prosulfocarb, trifluralin, and pyroxasulfone. T1 and A18 were 17.9- and 20-fold more resistant to triallate than susceptible SLR4. The level of resistance detected in T1 to prosulfocarb (5.9-fold) and pyroxasulfone (4-fold) was lower compared to A18, which displayed 12.1- and 7.8-fold resistance to both herbicides, respectively. Despite resistance, the mixture of two different preplant-incorporated (PPI) site-of-action herbicides improved rigid ryegrass control and wheat yield compared to a single PPI herbicide only. Prosulfocarb + triallate and prosulfocarb + S-metolachlor + triallate did not reduce rigid ryegrass seed set when compared to prosulfocarb applied alone at the higher rate (2,400 g ai ha–1). Pyroxasulfone + triallate PPI followed by glyphosate (1,880 g ai ha-1) as a weed seed set control treatment reduced rigid ryegrass seed production by 93% and 95% at both sites, respectively. These herbicides also significantly improved grain yield of wheat at Paskeville (22%) and Arthurton (38%) compared to the untreated.


2009 ◽  
Vol 148 (2) ◽  
pp. 217-223 ◽  
Author(s):  
E. K. LIU ◽  
B. Q. ZHAO ◽  
X. R. MEI ◽  
H. B. SO ◽  
J. LI ◽  
...  

SUMMARYField experiments (15 years) were carried out to study the effects of no-tillage (NT) and conventional tillage (CT) management practices on the soil chemical properties, microbial biomass, soil enzymatic activities and winter wheat yield on a cinnamon soil in Shanxi, on the Chinese Loess Plateau. Compared to CT, NT increased soil organic carbon, soil total nitrogen and soil total phosphorus in the 0–100 mm layer by 25, 18 and 7%, respectively. Microbial biomass C and N contents under NT were 41 and 57% greater than under CT on the same layer. In general, higher enzymatic activities were found in the more superficial layers of soil under NT than under CT in the same layer. Winter wheat yield wasc. 20% higher under NT than under CT. These findings have implications for understanding how conservation tillage practices improve soil quality and sustainability in the rainfed dryland farming areas of northern China.


2002 ◽  
Vol 53 (5) ◽  
pp. 587 ◽  
Author(s):  
Víctor Sadras ◽  
David Roget ◽  
Garry O'Leary

The responses of wheat grain yield to soil properties, weather, root diseases, and management practices were investigated in 75 grower-managed crops in the Mallee region of South Australia, Victoria, and New South Wales during 3 growing seasons. Fourteen cultivars were represented in the sampled crops, with Frame being the most common (56%). The most widespread crop sequence was wheat after pasture (43% of wheat crops), followed by wheat after fallow or cereal (both about 20%); 12% of the wheat was sown after legumes. Wheat after cereal was more common in drier sites, and wheat after fallow in wetter sites. Wheat yield was proportional to Fischer’s photothermal coefficient around flowering, and ranged from nil to 4.7 t/ha. On average, wheat crops sown after cereals yielded 0.4 t/ha less than their counterparts sown after fallow, and 0.7 t/ha less than those after legumes. Sowing date ranged from 24 April to 21 July; yield declined with delayed sowing at an average rate of 17 kg/ha.day. Growing season rainfall (April–October) ranged from 111 to 266 mm, and accounted for 27% of the variation in grain yield. Soil water content at sowing (0–1 m) ranged from 32 to 330 mm; yield increased with initial soil water at an average rate of 6 kg/ha.mm. Grain yield per unit growing season rainfall was generally low, with 75% of crops producing <12 kg grain/ha.mm; the maximum ratio was 21 kg/ha.mm. Soil constraints, including sodicity, alkalinity, salinity, and boron toxicity, reduced yield in part by reducing availability of stored soil water. Owing to severity of chemical constraints increasing with soil depth, grain yield and yield per unit growing season rainfall were both inversely related to the proportion of water stored deeper in the soil (0.5–1 m). Yield was unrelated to nitrogen, both initial and applied. Larger amounts of nitrogen accumulated in soils with more severe constraints partially accounted for the lack of association between yield and nitrogen.


2007 ◽  
Vol 145 (3) ◽  
pp. 223-227 ◽  
Author(s):  
M. P. REYNOLDS ◽  
P. R. HOBBS ◽  
H. J. BRAUN

Wheat is grown on 210 million ha throughout the world producing approximately 600 million tonnes of grain (10 year average; FAO 2005) and providing on average one fifth of the total calorific input of the world's population (FAO 2003). For some regions such as North Africa, Turkey and Central Asia, wheat provides half of total dietary energy intake. Of the cultivated wheat area, half is located in less developed countries where there have been steady increases in productivity since the green revolution, associated with genetic improvements in yield potential, resistance to diseases and adaptation to abiotic stresses (Reynolds & Borlaug 2006a, b) as well as better agronomic practices (Derpsch 2005). Nonetheless, challenges to wheat production are still considerable, especially in the developing world, not only because of increased demand but also because of the increased scarcity of water resources (Rosegrant 1997; WMO 1997), ever more unpredictable climates (Fischer et al. 2002), increased urbanization and loss of good quality land away from agriculture (Hobbs 2007), and decreased public sector investment in agriculture and rural affairs (Falcon & Naylor 2005). To meet demand in a sustainable way, more resources are required to breed a new generation of genetically improved cultivars as well as implement resource-conserving agronomic management practices.


Author(s):  
L. S. Sampaio ◽  
R. Battisti ◽  
M. A. Lana ◽  
K. J. Boote

Abstract Crop models can be used to explain yield variations associated with management practices, environment and genotype. This study aimed to assess the effect of plant densities using CSM-CROPGRO-Soybean for low latitudes. The crop model was calibrated and evaluated using data from field experiments, including plant densities (10, 20, 30 and 40 plants per m2), maturity groups (MG 7.7 and 8.8) and sowing dates (calibration: 06 Jan., 19 Jan., 16 Feb. 2018; and evaluation: 19 Jan. 2019). The model simulated phenology with a bias lower than 2 days for calibration and 7 days for evaluation. Relative root mean square error for the maximum leaf area index varied from 12.2 to 31.3%; while that for grain yield varied between 3 and 32%. The calibrated model was used to simulate different management scenarios across six sites located in the low latitude, considering 33 growing seasons. Simulations showed a higher yield for 40 pl per m2, as expected, but with greater yield gain increments occurring at low plant density going from 10 to 20 pl per m2. In Santarém, Brazil, MG 8.8 sown on 21 Feb. had a median yield of 2658, 3197, 3442 and 3583 kg/ha, respectively, for 10, 20, 30 and 40 pl per m2, resulting in a relative increase of 20, 8 and 4% for each additional 10 pl per m2. Overall, the crop model had adequate performance, indicating a minimum recommended plant density of 20 pl per m2, while sowing dates and maturity groups showed different yield level and pattern across sites in function of the local climate.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yang Su ◽  
Benoit Gabrielle ◽  
Damien Beillouin ◽  
David Makowski

AbstractConservation agriculture (CA) has been promoted to mitigate climate change, reduce soil erosion, and provide a variety of ecosystem services. Yet, its impacts on crop yields remains controversial. To gain further insight, we mapped the probability of yield gain when switching from conventional tillage systems (CT) to CA worldwide. Relative yield changes were estimated with machine learning algorithms trained by 4403 paired yield observations on 8 crop species extracted from 413 publications. CA has better productive performance than no-till system (NT), and it stands a more than 50% chance to outperform CT in dryer regions of the world, especially with proper agricultural management practices. Residue retention has the largest positive impact on CA productivity comparing to other management practices. The variations in the productivity of CA and NT across geographical and climatical regions were illustrated on global maps. CA appears as a sustainable agricultural practice if targeted at specific climatic regions and crop species.


2012 ◽  
Vol 151 (1) ◽  
pp. 105-118 ◽  
Author(s):  
M. SANCHEZ-GARCIA ◽  
C. ROYO ◽  
N. APARICIO ◽  
J. A. MARTÍN-SÁNCHEZ ◽  
F. ÁLVARO

SUMMARYA collection of 26 wheat genotypes widely grown in Spain during the 20th century was evaluated in eight contrasting environments in order to quantify breeding achievements in yield and associated traits. From 1930 to 2000, yield increased at a rate of 35·1 kg/ha/yr or 0·88%/yr, but estimations of relative genetic gain (RGG) were environment-dependent. RGG estimated for yield were positively associated with the average minimum daily temperatures from sowing to heading in the testing environments (R2 = 0·81; P < 0·01). The number of grains/spike and the number of spikes/m2 increased at a rate of 0·60%/yr and 0·30%/yr, respectively, while grain weight remained unchanged. The present study detected two main episodes of yield improvement during the century. The first one coincided with the introduction, during the 1950s, of the first improved cultivars derived from intra-specific crosses, which increased the yield of landraces by 30% due to an increase of c. 58% in the number of grains/spike, accompanied by a 16% reduction in grain weight. These initial cultivars (termed ‘old-bred’ in a previous study by Sanchez-Garcia et al. 2012) exhibited a higher harvest index (HI), increased from 0·25 to 0·40, but maintained the same aboveground biomass at maturity as the landraces (despite reducing both plant height and the number of tillers/plant) due to increases in the proportion of tillers bearing spikes. The second yield gain occurred after the introduction, in the early 1970s, of semi-dwarf germplasm from CIMMYT (International Maize and Wheat Improvement Centre) and some French cultivars. This new germplasm further reduced plant height, improved HI up to 0·45 and increased the number of tillers/plant while maintaining their rate of fertility, thus resulting in a yield gain of c. 37%. The cultivars released during the last decade of the century did not contribute to significant yield improvements.


1996 ◽  
Vol 36 (5) ◽  
pp. 555
Author(s):  
ID Black ◽  
CB Dyson ◽  
AR Fischle

In 11 experiments over 6 seasons the herbicide sethoxydim was applied to Machete, Spear and Blade wheat cultivars in the absence or near absence of weeds (10 sites) or where the weeds were controlled by selective herbicides (1 site), in the cropping area north of Adelaide, South Australia. The rates applied included 9-47 g a.i./ha at the 2-3 leaf growth stage and 9-74 g a.i./ha at early tillering. Except for the very long growing season of 1992, there was a highly significant positive linear correlation between the number of degree days in the growing season at each experimental site and relative mean yield increase of these sethoxydim treatments. Yield increases ranged from nil in growing seasons of about 1000 degree days to 32% in a growing season of 1480 degree days, with a median of 8% over the experiments.


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