Zobrazeno 1 - 10
of 95
pro vyhledávání: '"J. van Biljon"'
Publikováno v:
Advanced Technologies and Societal Change ISBN: 9789811987373
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::5e52296434aa106b75d17273e25a0a72
https://doi.org/10.1007/978-981-19-8738-0_11
https://doi.org/10.1007/978-981-19-8738-0_11
Publikováno v:
Lecture Notes in Networks and Systems ISBN: 9783031104664
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::00a468906518187a31c40903be0d7b22
https://doi.org/10.1007/978-3-031-10467-1_16
https://doi.org/10.1007/978-3-031-10467-1_16
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Akademický článek
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Publikováno v:
South African Journal of Plant and Soil. 27:252-255
South African farmers commenced applying zinc (Zn) during the 1960s at a rate of approximately 2 kg Zn ha−1. Although good yields were produced and Zn levels increased in South African maize fields, a recent survey revealed that maize meal containe
Autor:
J. J. van Biljon
Publikováno v:
South African Journal of Plant and Soil. 27:32-36
Maize yield as well as fertilizer practices have changed over the last 25 years. Average maize yield for South Africa increased from approximately 2.3 tons ha−1 in the early 1980s to approximately 3.5 tons ha−1 in recent years. The early 1970s to
Threshold values and sufficiency levels for potassium in maize producing sandy soils of South Africa
Publikováno v:
South African Journal of Plant and Soil. 25:65-70
South African maize farmers apply only two thirds of the potassium (K) which is annually removed in the grain, causing a deficit of more than 13 000 tons K per season. It is expected that these maize fields will gradually become depleted and more K w
Publikováno v:
South African Journal of Plant and Soil. 25:8-13
There is still no consensus in South Africa on the parameters used to advise maize farmers on the quantity of N needed for optimum yields. In order to determine the lower and upper threshold values for nitrogen (N), the biological optimum and the min
Publikováno v:
South African Journal of Plant and Soil. 24:228-232
Results of the first plantings of field trials conducted at six localities on sandy soils in the Free State Province of South Africa are presented. The effective cation exchange capacity (ECEC) and Ca2+, Mg2+, K+ as a percentage of the soils ECEC (Ca
Publikováno v:
South African Journal of Plant and Soil. 21:152-156
Fertilizers introduced to South Africa after World War 2 contained sufficient sulphur (S) to satisfy the demands of all crops. However, dramatic shifts to high-analysis NPK fertilizers containing little or no S and restriction on sulphur dioxide emis