Effects of seedbed properties on crop emergence: 1. Temporal effects of temperature and sowing depth in seedbeds with favourable properties

Abstract Rapid and uniform crop establishment is a prerequisite for efficient crop production and minimal environmental impact. Experiments were carried out in shallow plastic boxes placed directly on the ground in the field for studies of the effects of seedbed properties on emergence of various crops. This paper presents an analysis of the time required for germination and emergence under near-optimal seedbed conditions. The crops studied were barley, oats, wheat, pea, rape seed, white mustard, sugar beet, red clover and timothy. The time required for germination generally increased with size of the seeds, presumably because larger seeds needed more water to initiate germination. This applied both when comparing different crops and different seed sizes of the same crop. However, considerable differences occurred between seed lots of the same crop and there were greater differences between seed lots of the same crop than between the three small grain crops studied. Growth rate of the seedlings generally increased with seed size, presumably because of increased energy content in the seed. Consequently, the most rapid emergence was obtained from small seeds at shallow sowing and from large seeds at deep sowing. The crops studied had a minimum temperature for germination and seedling growth close to 0 °C. Under optimal seedbed conditions, thermal time required for 50% germination of barley was typically about 65 °C days over this base temperature and for seedling growth about 6 °C days cm−1. From 4 cm sowing depth, about 80 °C days were required for emergence but with considerable variations between seed lots. For rape seed or white mustard about 40 °C days were required for germination and about 8 °C days cm−1 for the seedling growth.

[1]  Roger W. Payne,et al.  Modelling the effect of soil moisture on germination and emergence of wheat and sugar beet with the minimum number of parameters , 2005 .

[2]  Carolyne Dürr,et al.  Analysis of the variability of sugar beet (Beta vulgaris L) growth during the early stages. I: Influence of various conditions on crop establishment , 1992 .

[3]  G. Squire,et al.  Non-linearity in rate-temperature relations of germination in oilseed rape , 1996 .

[4]  W. R. Whalley,et al.  Effects of seed priming, aggregate size and soil matric potential on emergence of cotton (Gossypium hirsutum L.) and maize (Zea mays L.) , 2003 .

[5]  R. Ellis,et al.  Alternating Temperatures and Rate of Seed Germination in Lentil , 1994 .

[6]  Inge Håkansson,et al.  A review of research on seedbed preparation for small grains in Sweden , 2002 .

[7]  R. J. Gummerson.  The Effect of Constant Temperatures and Osmotic Potentials on the Germination of Sugar Beet , 1986 .

[8]  G. D. Johnson,et al.  Determining the Feasibility of Early Seeding Canola in the Northern Great Plains , 2005 .

[9]  D. Harris,et al.  The effects of manure, genotype, seed priming, depth and date of sowing on the emergence and early growth of Sorghum bicolor (L.) Moench in semi-arid Botswana , 1996 .

[10]  A. Bouaziz,et al.  Modeling Wheat Seedling Growth and Emergence: I. Seedling Growth Affected by Soil Water Potential , 1989 .

[11]  Jean Roger-Estrade,et al.  A review of tillage effects on crop residue management, seedbed conditions and seedling establishment , 2001 .

[12]  J. Boiffin,et al.  Analysis of the variability of sugar beet (Beta vulgaris L) growth during the early stages. II. Factors influencing seedling size in field conditions , 1992 .

[13]  K. Phelps,et al.  Germination and post-germination growth to carrot seedling emergence: predictive threshold models and sources of variation between sowing occasions , 1998 .

[14]  S. Håkansson,et al.  Weeds and Weed Management on Arable Land: An Ecological Approach , 2003 .

[15]  J. Annandale,et al.  Thermal time requirements for the development of green pea (Pisum sativum L.) , 1998 .

[16]  A. Hadas.  Factors affecting seed germination under soil moisture stress. , 1970 .

[17]  M. Durrant,et al.  Factors associated with germination of sugar-beet seed in the standard test and establishment in the field , 1990 .

[18]  A. Bouaziz,et al.  Modeling of Wheat Imbibition and Germination as Influenced by Soil Physical Properties , 1989 .

[19]  A. Bouaziz,et al.  Modeling Wheat Seedling Growth and Emergence: II. Comparison with Field Experiments , 1989 .

[20]  I. Håkansson,et al.  Experiments on the effects of seedbed characteristics on seedling emergence in a dry weather situation , 1984 .

[21]  C. Pearson,et al.  Thermal requirement for germination and seedling growth of wheat , 1992 .

[22]  D. Harris,et al.  Development and Testing of “On‐Farm” Seed Priming , 2006 .

[23]  Base Temperature and Growing‐Degree‐Hour Requirements for the Emergence of Canola , 1997 .

[24]  S. Seefeldt,et al.  Base growth temperatures, germination rates and growth response of contemporary spring wheat (Triticum aestivum L.) cultivars from the US Pacific Northwest , 2002 .