No-till crop establishment on red earth soils at Katherine, Northern Territory: effect of sowing depth and firming wheel pressure on the establishment of cowpea, mung bean, soybean and maize

1989 ◽  
Vol 29 (3) ◽  
pp. 397 ◽  
Author(s):  
DG Abrecht

The effect of sowing depth and firming wheel pressure of a no-till planter on the emergence and seedling growth of soybean, cowpea, mung bean and maize was examined in a red earth soil at Katherine, Australia. Each species was planted in a factorial combination of 3 sowing depths (60, 80, 100 mm) and 3 seed firming wheel pressures (1, 6, 11 kg/cm tyre width). Hot, dry conditions for 14 days after sowing resulted in rapid drying of the soil and high soil temperature. Most seed germinated but there was considerable variation in seedling emergence. Good seedling emergence of mung bean (96%) and cowpea (95%) contrasted with poorer emergence of soybean (57%) and maize (50%). Maize germinated more slowly than the grain legumes and unemerged seedlings had ceased growing when the coleoptiles were < 10 mm long. Soybean germinated rapidly and hypocotyls of the unemerged seedlings had stopped growing within 20 mm of the soil surface. The development of maize and soybean seedlings may have been retarded by high temperatures and severe soil water deficits. Deep planting slowed emergence but increased seedling growth in maize and soybean. The effect was most evident in soybean. Firming wheel pressure did not influence the soil strength below the planted seed and did not significantly affect seed germination, seedling emergence or seedling growth.

1985 ◽  
Vol 105 (3) ◽  
pp. 535-541 ◽  
Author(s):  
D. C. E. Wurr ◽  
Jane R. Fellows ◽  
L. P. Bufton

SUMMARYPelleted seed of the crisp lettuce variety Pennlake was sown on five occasions with units from either the experimental dibber drill designed by the National Institute of Agricultural Engineering or a Stanhay S870 drill. There were three dibber-drill treatments: seeds left in open holes or covered with peat–vermiculite or perlite. Seedling emergence and growth from each sowing of the four drill treatments were compared under different moisture regimes.There were large differences between drill treatments in emergence percentage, time to emergence of 50% of the seedlings which emerged (t50) and seedling weight at all sowings but there was a significant effect of drill treatment on the standard deviation of seedling emergence times at only one sowing. Of the dibber-drill treatments, only very occasionally did open holes or perlite cover give significantly better emergence than peat-vermiculite cover, which gave the most consistent results. In general, the dibber drill with peat-vermiculite cover gave significantly faster and higher emergence and heavier seedlings than the Stanhay drill. Differences in percentage seedling emergence tended to be greater under dry conditions.


1993 ◽  
Vol 44 (6) ◽  
pp. 1311 ◽  
Author(s):  
GM Lodge ◽  
AJ Schipp

Two experiments examined the effects of sowing time and depth (surface and 10, 25, 50 mm) on emergence of Danthonia richardsonii Cashmore and Danthonia linkii Kunth. Experiment 1 was conducted from January to December 1990 on a loam/sand mixture in boxes. Emergence was highest in both species for seeds sown onto the soil surface in summer and autumn (P < 0.05). Sowing at any depth at any time of the year, or surface sowing in winter and spring, markedly reduced emergence. Experiment 2 was conducted in the field at Tamworth, northern New South Wales from September 1991 to August 1992, on a red brown earth and a black earth. This study confirmed that emergence in both species was highest from surface sown seed. Field emergence was lowest in winter, but in contrast to experiment 1, it was higher in spring, particularly on the black earth. Seedling emergence appeared to be related to mean maximum temperature, decreasing in winter as it declined below 20�C, and increasing in spring when it was greater than 23�C. Differences in seed weight were reflected in emergence of D. richardsonii and D. linkii in experiment 1. Similar emergence was recorded for the loamlsand mixture and sand, indicating that there was little effect of texture. Phalaris aquatica L. cv. Sirosa surface sown in December had lower emergence ( P < 0.05) than both Danthonia spp., but emergence of this larger seeded cultivar was higher at depths of 10 and 25 mm. Laboratory studies to determine reasons for the low emergence of D. richardsonii and D. linkii from depth, indicated that neither had an obligate light requirement for germination. Depth, however, reduced germination (P < 0.05) compared with surface sowing of seed. Seedlings at depth also were observed to have slower rates of shoot and root elongation. In the field, the most successful establishments of D. richardsonii and D. linkii seedlings are likely to occur from surface sowings in April and May. Sowing in spring may also be possible if mean maximum soil temperatures exceed 23�C, and seedlings can establish before the onset of hot, dry conditions in summer.


Botany ◽  
2018 ◽  
Vol 96 (5) ◽  
pp. 319-328 ◽  
Author(s):  
Jeremi Kołodziejek ◽  
Jacek Patykowski ◽  
Mateusz Wala

The germination requirements of four taxonomically related taxa of Dianthus (D. arenarius L. subsp. borussicus Vierh., D. carthusianorum L., D. gratianopolitanus Vill., and D. deltoides L.) were studied under controlled conditions in a laboratory. A set of experiments were conducted to evaluate seed germination responses to storage period and cold stratification, different hydrogen ion concentrations (pH), potassium nitrate ([Formula: see text]), temperatures, and light conditions. Experiments were also performed to study the effects of sowing depth and water supply on seedling emergence. There were no differences in germination between seeds incubated under light or dark conditions for any of the taxa we studied. Germination percentages increased significantly with increases in temperature. The taxa of Dianthus we studied showed similar responses to sand burial, i.e., seeds placed on or near the soil surface had maximum emergence, and emergence declined with increasing depth of seed burial. In the studied taxa, germination was reduced by declining osmotic potentials. Cold stratification increased the germination rate, but did not affect final germination percentage of Dianthus seeds. A higher concentration of nutritious solutions (KNO3) negatively affected the germination percentage. The results show that seeds of the studied taxa are potentially germinable in the species’ habitat at any time between April and October.


1969 ◽  
Vol 9 (39) ◽  
pp. 422 ◽  
Author(s):  
A Lazenby ◽  
JMA Schiller

A study was made in seed boxes at Armidale, New South Wales, on a red earth soil, of the effects of two soil tilths (particles<0.3 cm and between 0.6 and 1.25 cm), three seeding depths (surface seeding, 1.25 cm and 2.5 cm), and three levels of applied phosphorus (the equivalents of phosphorus in nil, 378 kg/ha and 756 kg/ha superphosphate, applied as sodium di-hydrogen phosphate) on emergence and early seedling growth of Phalaris tuberosa. Water was made non-limiting as far as practicable. Seedling counts were made every four days until the first harvest, 32 days after sowing. Four fortnightly destructive harvests were made to examine treatment effects on post-emergence seedling growth. Seeding into the fine tilth at a depth of 1.25 cm on the high phosphorus treatment gave the fastest and highest total seedling emergence. Conditions most favourable to immediate post-emergence seedling growth were sowing into a fine seedbed at a depth of 1.25 cm or 2.5 cm in combination with phosphorus ; the rate of seedling growth increased with rate of phosphorus applied.


2017 ◽  
Vol 65 (1) ◽  
pp. 22 ◽  
Author(s):  
Lorena Ruiz Talonia ◽  
Nick Reid ◽  
Caroline L. Gross ◽  
R. D. B. Whalley

We examined the potential of direct-seeding Eucalyptus species to revegetate the vertosol (‘cracking clay’) soils that characterise the floodplains of north-western New South Wales. We investigated the influence of sowing depth (0, 6, 12 and 20 mm) and three soil-moisture scenarios (dry, moist and flooded) on seedling emergence of seedlings of six species of Eucalyptus with a range of seed sizes (E. blakelyi, E. camaldulensis, E. melanophloia, E. melliodora, E. pilligaensis and E. populnea). We used cracking clay soil from the region in a glasshouse environment. Seedling emergence was low despite high seed viability and provision of optimum temperatures and soil moisture conditions. All six species exhibited greatest emergence when sown at 0–6-mm depth, with seed size being less important than moisture (except under dry conditions) and proximity to the surface. Species responded differently to the three watering treatments. Eucalyptus melanophloia exhibited greatest emergence in the ‘dry’ watering treatment. The floodplain species, E. camaldulensis, E pilliganesis and E. populnea, had the greatest emergence under flood conditions. Eucalyptus blakelyi and E. melliodora exhibited intermediate emergence in relation to all three soil-moisture regimes. Although the direct seeding of these species in vertosol soils in the region may be successful on occasion, windows of opportunity will be infrequent and the planting of seedling tubestock will be more reliable for revegetation.


Weed Science ◽  
1997 ◽  
Vol 45 (1) ◽  
pp. 120-126 ◽  
Author(s):  
Joseph O. E. Oryokot ◽  
Stephen D. Murphy ◽  
Clarence J. Swanton

We studied the effect of no-till, chisel, and moldboard plow and the presence or absence of corn on soil temperature, moisture and, subsequently, the emergence phenology and density of pigweed seedlings at 2 sites from 1993 to 1995 inclusively. Tillage significantly affected the phenology of pigweed seedling emergence only during a June drought at one site in 1994. Soil temperature and moisture, measured at 2.5-cm depths, also were unaffected by tillage. Weed phenology is usually earlier in no-till because more seeds are located closer to the surface (< 5 cm deep) in no-till, thereby reducing the delay in penetrating through the soil, and because soil temperatures and moisture are nearer the germination and emergence optima. However, pigweed seedlings are already physiologically restricted to germination depths of less than 2.5 cm regardless of tillage; therefore, this prior constraint eliminated any potential differences in emergence phenologies caused by tillage. The presence or absence of corn also did not affect soil temperatures, soil moisture, or pigweed seedling emergence phenologies. Pigweed seedling density was significantly higher in no-till; this may have been caused by increased numbers of seeds near the soil surface in no-till. The presence or absence of corn did not affect pigweed seedling density; the lack of a significant effect probably reflects high variances in density. Although necessary for most weed species, tillage may be a less important factor to consider in predicting pigweed population dynamics and subsequent management recommendations.


1992 ◽  
Vol 32 (2) ◽  
pp. 183 ◽  
Author(s):  
SR Walker ◽  
VA Osten ◽  
DW Lack ◽  
L Broom

The residual phytotoxicity of 2,4-D mine and dicamba to sorghum (Sorghum bicolor L.) and sunflowers (Helianthus annuus L.) was investigated under central Queensland conditions of variable rainfall and high temperatures. Effects of soil water content, sowing depth, and leaching in clay soils were determined. Phytotoxicity, as measured by decreases in shoot dry matter in pots, increased with herbicide rate and decreased rapidly in moist soil (34% w/w) but was maintained for at least 14 days in dry soil (114% w/w). 2,4-D and dicamba were phytotoxic when leached into the soil but not when they remained on the soil surface. Seedling growth and yield were not affected by 2 kg 2,4-Dha applied at 7 or more days pre-sowing, or by 0.5 kg 2,4-D/ha and 0.14 kg dicamba/ha applied at 1 day pre-sowing, in 5 field environments. When either herbicide was applied at higher rates 1 day pre-sowing, seedling growth was reduced if 25 mm of irrigation was received within 4 days of sowing, and yields were reduced in the field environment that received 144 mm of rainfall within 14 days of sowing.


Author(s):  
K.H. Widdup ◽  
T.L. Knight ◽  
C.J. Waters

Slow establishment of caucasian clover (Trifolium ambiguum L.) is hindering the use of this legume in pasture mixtures. Improved genetic material is one strategy of correcting the problem. Newly harvested seed of hexaploid caucasian clover germplasm covering a range of origins, together with white and red clover and lucerne, were sown in 1 m rows in a Wakanui soil at Lincoln in November 1995. After 21 days, the caucasian clover material as a group had similar numbers of emerged seedlings as white clover and lucerne, but was inferior to red clover. There was wide variation among caucasian clover lines (48-70% seedling emergence), with the cool-season selection from cv. Monaro ranked the highest. Recurrent selection at low temperatures could be used to select material with improved rates of seedling emergence. Red clover and lucerne seedlings produced significantly greater shoot and root dry weight than caucasian and white clover seedlings. Initially, caucasian clover seedlings partitioned 1:1 shoot to root dry weight compared with 3:1 for white clover. After 2 months, caucasian clover seedlings had similar shoot growth but 3 times the root growth of white clover. Between 2 and 5 months, caucasian clover partitioned more to root and rhizome growth, resulting in a 0.3:1 shoot:root ratio compared with 2:1 for white clover. Both clover species had similar total dry weight after 5 months. Unhindered root/ rhizome devel-opment is very important to hasten the establishment phase of caucasian clover. The caucasian clover lines KZ3 and cool-season, both selections from Monaro, developed seedlings with greater shoot and root growth than cv. Monaro. KZ3 continued to produce greater root growth after 5 months, indicating the genetic potential for improvement in seedling growth rate. Different pasture estab-lishment techniques are proposed that take account of the seedling growth characteristics of caucasian clover. Keywords: establishment, genetic variation, growth, seedling emergence, Trifolium ambiguum


2017 ◽  
Vol 45 (2) ◽  
pp. 282-295
Author(s):  
R. Vihotogbé ◽  
C. Watson ◽  
R. Glèlè Kakaï ◽  
F. Wichern ◽  
B. Sinsin ◽  
...  

Author(s):  
V. P. Belobrov ◽  
S. А. Yudin ◽  
V. А. Kholodov ◽  
N. V. Yaroslavtseva ◽  
N. R. Ermolaev ◽  
...  

The influence of different systems of soil cultivation is considered - traditional (recommended) technology and direct sowing, which is increasingly used under dry conditions of the region. The rehabilitation of the degraded southern chernozems and dark chestnut soils structure during 13 and 7 years of direct sowing, respectively, has not been established. It takes much longer to rehabilitation the aggregate state of soils, which is currently in a critical condition of the content of aggregates> 10 mm in size and the sum of agronomically valuable aggregates. The soils under 60-year treeline, as a control, showed a satisfactory range of aggregates, which indicates a high degree of soil degradation in the past and a long period of their recovery time. The effectiveness of direct sowing usage in the cultivation of a wider range of grain and row crops (winter wheat, sunflower, peas, chickpeas, rapeseed, buckwheat, corn) is due to the peculiarities of agricultural technologies. Abandoning of naked fallows and soil treatments with the simultaneous use of plant residues and cover crops on the soil surface between the harvest and sowing of winter crops provides an anti-erosion effect and, as a consequence, a decrease in physical evaporation, an increase in moisture and biota reserves, an increase in microbiological processes, which are noted in the form trends in improving the agrochemical and agrophysical properties of soils.


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