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SUMMARY:Impact of long-term effects of wheat production management practic
 es on soil acidity\, P and some micronutrients in a semi-arid Plinthosol
DTSTART;VALUE=DATE-TIME:20141002T104500Z
DTEND;VALUE=DATE-TIME:20141002T110000Z
DTSTAMP;VALUE=DATE-TIME:20261006T145512Z
UID:indico-contribution-3956@events.saip.org.za
DESCRIPTION:Speakers: Palo Francis Loke (Department of Soil\, Crop and Cli
 mate Sciences\, University of the Free State)\nFarmers continuously remove
  crop residues for use as building materials\, fuel and animal feed or bed
 ding as well as to avoid difficulties during tillage operations. Therefore
 \, demonstrations of the benefits of recycling crop residues are necessary
 . The aim with this study was to evaluate the influence of different wheat
  production management practices on acidity and some essential nutrients f
 rom a long-term trial on a Plinthosol in semi-arid South Africa. The trial
  was set up in 1979\, and since then two methods of straw management (unbu
 rned and burned)\, three methods of tillage (no-tillage\, stubble mulch\, 
 and plough)\, two methods of weed control (chemical and mechanical)\, and 
 three levels of nitrogen (N) fertilizer (20\, 40 and 60 kg ha–1) have be
 en applied. Soil samples were collected in June 2010 at depths of 0–50\,
  50–100\, 100–150\, 150–250\, 250–350 and 350–450mm from plots t
 hat received 40 kg N ha-1 and were analyzed for pH\, phosphorus (P)\, copp
 er (Cu)\, iron (Fe)\, manganese (Mn) and zinc (Zn). Results obtained showe
 d that straw burning resulted in higher P and Mn but lower Cu than no-burn
 ing. No-tillage\, and to some extent stubble mulch\, suppressed soil acidi
 fication and increased P and Zn compared with ploughing\, especially in th
 e surface layers where crop residues accumulate. In contrast\, mouldboard 
 ploughing and stubble mulch increased Cu more than no-tillage\, possibly d
 ue to the strong affinity of organic matter for Cu. Tillage effects on Mn 
 were inconsistent and difficult to explain. Chemical weeding also improved
  P\, probably because of the pesticide application\, but resulted in lower
  pH and Cu values compared with mechanical weeding. Treatment combinations
  also had an influence on P and\, to a lesser extent\, on soil pH and Cu\,
  which might be due to the higher organic matter present in no-tilled soil
 s. Irrespective of straw management or weed-control methods\, no-tillage r
 esulted in higher P than did ploughing and stubble mulch. Nutrient concent
 rations and pH values were sufficient for wheat growth under all treatment
 s. However\, although the nutrients were highest under straw burning\, no-
 tillage and\, to some extent\, stubble mulch\, wheat yield was higher with
  unburned straw and mouldboard ploughing. Therefore\, an integrated approa
 ch from various disciplines is recommended to identify and rectify yield-l
 imiting factors under conservation tillage systems.\n\nKEYWORDS: nutrients
 \, soil pH\, straw management\, tillage\, weed control\n\nhttps://events.s
 aip.org.za/event/40/contributions/3956/
LOCATION:Matjiesfontein's Lord Milner Hotel Conference Room\, Matjiesfonte
 in Station
URL:https://events.saip.org.za/event/40/contributions/3956/
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