Biomass production, yield and quality response of spring wheat to soil tillage, crop rotation and nitrogen fertilisation in the Swartland wheat producing area of South Africa

Maali, Safiah Hasan

Biomass production, yield and quality response of spring wheat to soil tillage, crop rotation and nitrogen fertilisation in the Swartland wheat producing area of South Africa

dc.contributor.advisor	Agenbag, G. A.
dc.contributor.author	Maali, Safiah Hasan
dc.contributor.other	University of Stellenbosch. Faculty of Agrisciences. Dept. of Agronomy.	en_ZA
dc.date.accessioned	2010-05-24T06:16:16Z
dc.date.available	2010-05-24T06:16:16Z
dc.date.issued	2003-03
dc.description	Thesis (PhD(Agric) (Agronomy))--University of Stellenbosch, 2003.	en_ZA
dc.description.abstract	ENGLISH ABSTRACT: A long term experiment was conducted at the Langgewens Experimental Farm, near Malmesbury in the Western Cape province of the Republic of South Africa. The effect of soil tillage, crop rotation and nitrogen fertiliser rates on mineral-N levels in the soil, nitrogen levels in plants, wheat growth and yield components, grain yield as well as quality parameters of spring wheat were determined. Although the tillage treatments tested were initiated in 1976, present crop rotations and nitrogen application rates were only applied since 1990. Most of the data that are discussed however was recorded during the 1997 to 2001 period. The trial was designed as a randomised complete block with a split-plot arrangement and four replicates. Main plots were tillage methods namely conventional tillage (CT), tine tillage (TT), minimum tillage (MT) and no tillage (NT). Crop rotations used were continuous wheat (WW) and wheatl lupin/wheat/canola (WLWC). Both soil and crop data were recorded. The results of this study showed the differences in total mineral-N content of the soil. N-contents of wheat, wheat growth and yield components as well as wheat quality parameters were found between tillage treatments, crop rotations used as well as N- fertiliser rates applied. Response however, varied largely between years due to annual variation in especially total precipitation and distribution of rainfall. The inclusion of a legume crop (lupin) and canola in the rotation with wheat was found to have only a small effect probably due to the fact that lupins were grown once in a four year cycle only. Application of different nitrogen rates did increase the mineral-N in the soil, but the effect did not last very long in most years due to either N-leaching or plant uptake. To ensure sufficient mineral-N levels, late application of N-fertiliser will therefore be needed. Minimum tillage or reduced tillage performs better than conventional tillage in low rainfall years. In general these tillage systems should be combined with crop rotation to ensure that yields are comparable to that obtained with conventional tillage.	en
dc.description.abstract	AFRIKAANSE OPSOMMING: Die ontwikkeling, graanopbrengs en bakkwaliteit van koring (Tritium aestivum L.) in reaksie teenoor gewasratasie, metode van grondbewerking en N-bemestingspeil is in 'n lang tennyn sllldie op Langgewens Proefplaas, naby Malmesbury in die Weskaap provinsie van die Republiek van Suid-Afrika, bepaal. Hoewel die verskillende grand bewcrkingsmetodes sedert 1976, en gewasrotasies en slikstofpeile sedert 1990 toegepas is, is daar in hierdie studie gekonsentreer op data wal gcdurcnde die periode 1997-2001 ingesamel is. Die eksperiment is as 'n randomiseerde blok ontwerp met vier bewerkingsmetodes nl. konvcnsionele bewerking (CT), tand bewerking (TT). minimum bewerking (MT) en geen bewerking (NT), twee gewasratasies nl. monokuhuur koring (WW) en koring/lupienelkoringiCanola (WLWC) en drie N-peie (60 kg N ha- ', 100 kg N ha- 1 , 140 kg N ha- I uitgevoer. Aile stikstof is in die vorm van kalksteen-ammoniumnitraat toegedien. Die reaksie van beide grondfaktore soos die minerale N inhoud en gewaskomponente 5005 biomassa produksie, opbrengs en kwaliteit teenoor bogenoemde faktore het '0 goeie korrelasie getoon met die heersende klimaatstoestande. Lae reenval jare (gebiede) sal volgens hierdie stlldie die grootste voordeel verkry met minder intensiewe grand bewerkingstelsels. terwyl 'n frekwensie van meer as een peulgewas per siklus van 4 jaar nodig sal wees om grondvrllgbaarhcidsvlakke betekenisvol te verhoog. Stelsels van rninder intensiewe grondbewerking is ook tot 'n grater mate deur gewaswisseling bevoordeel as konvensionele melOdes van grondbewerking. Hocwel minerale-N vlakke in grond deur verskillende N-peile be'lnvloed is, was die efTektiwiteit van toedienings laag en het verdeelde tocdienings groat voordele ingehou.	af
dc.format.extent	1 v. (various foliations) : ill.
dc.identifier.uri	http://hdl.handle.net/10019.1/949
dc.language.iso	en	en_ZA
dc.publisher	Stellenbosch : University of Stellenbosch	en_ZA
dc.rights.holder	University of Stellenbosch	en_ZA
dc.subject	Theses -- Agronomy	en_ZA
dc.subject	Dissertations -- Agronomy	en
dc.subject.lcsh	Wheat -- Quality -- South Africa
dc.subject.lcsh	Wheat -- Yields -- South Africa
dc.subject.lcsh	Energy crops -- South Africa
dc.subject.lcsh	Tillage -- South Africa
dc.subject.lcsh	Crop rotation -- South Africa
dc.subject.lcsh	Crops and nitrogen
dc.subject.lcsh	Nitrogen fertilizers -- South Africa
dc.title	Biomass production, yield and quality response of spring wheat to soil tillage, crop rotation and nitrogen fertilisation in the Swartland wheat producing area of South Africa	en
dc.type	Thesis	en_ZA