Increased water productivity in irrigated tomato production in the smallholder farming community of Giyani

Pienaar, Cornelis Jacobus (2014-04)

Thesis (MScAgric)--Stellenbosch University, 2014.

Thesis

ENGLISH ABSTRACT: The availability of water for irrigation purposes is becoming a serious concern for smallholder famers in the former homeland areas of South Africa. Not only because of global weather change and the occurrence of more erratic weather events, but also due to competition for fresh water between the agricultural, industrial and domestic sectors (Hamdy et al., 2003). Food production increases in smallholder agriculture is seen as a possible solution to the food security challenges in the rural areas of the Limpopo Province (Altman et al., 2009). Smallholder farmers in Giyani mostly use traditional furrow irrigation systems and their farm crop productivity remains very low, compared to commercial farms in the same area. The objective of this study is to utilize and test various innovation technologies aimed at increasing Water Productivity (WP) in order to facilitate better irrigation management of the available water resources. The study was conducted on two farms, Zava Cooperative Garden and Mzilela Cooperative Garden, in the rural areas of Giyani over a two year period from 2012-2013. This study seeks to achieve the objective in three distinct ways. Firstly, the use of NIR technology is used to evaluate the prediction ability of soil chemical parameters for fertilizer requirement calculations. Secondly, WP trials were conducted on smallholder tomato (Solanum lycopersicum) production for three consecutive seasons, evaluating their current tomato crop production systems and also testing new innovations for WP increases. Thirdly, applying the MonQI methodology, inputs and outputs of all crop production sites were done to monitor the cropping systems throughout the period of the research. The results from this study indicate the importance of applying new innovations amongst smallholder production systems. Important findings from the NIR technologies indicated that this innovation can improve soil nutrient management in a more affordable, user friendly manner. The results showed that good prediction models were obtained for pH (KCl), electrical conductivity (EC), P, K, Mg, Na and CEC, with R2 and RPD values larger than 0.60 and 1.4 respectively. The prediction of exchangeable Ca was less successful with a R2 value of 0.43. Results from the WP trials suggest that drip irrigation performed better than furrow irrigation in terms of yield and WP. Yield and WP were very low for all treatments, being below 32 t/ha and 5.2 kg/m-3 respectively. Improved management practices, such as soil nutrient management and mulching were introduced in the 2nd and 3rd seasons of tomato trials in order to increase WP at field level at Mzilela farm. Results showed tomato yield increased from an average of 26.5 t/ha to 120.9 t/ha and WP increases from 4.61kg/m-3 to 17.69 kg/m-3. Deep drainage of water out of the rootzone decreased with better irrigation management. The results from the monitoring of inputs and output of their cropping systems revealed that smallholder farmers, using traditional farming practices, yielded very low and mostly below 5 t/ha for all crops. Some crops were totally lost due to hail and heat-waves. NPK balances for conventional cropping by the smallholder farmers at Mzilela was in the range of 0 to -70 kg/ha. The tomato production fertilized treatment of the 1st, 2nd and 3rd WP trials, showed positive nutrient balance results for P and K in the range of 80 to 140 kg/ha. N balances were mostly negative for all plots. NFI was R2768 and R4740 for season 1 and 3 respectively, while the 2nd season results showed a loss of - R5176. With the improved yield from the WP trial sites, and the fruits being sold to the Spar, the NFI increased to R42486 in the final season. The study concludes that great improvements in yield, WP and NFI are attainable and sustainable amongst smallholder farmers in the Giyani area.

AFRIKAANSE OPSOMMING: Die beskikbaarheid van water hulpbronne vir besproeiings doeleindes onder kleinskaalse boere in die voormalige tuislande is besig om ernstige bekommernisse te wek. Nie net as gevolg van globale weer veranderinge en meer gereelde ekstreme weer toestande nie, maar ook as gevolg van die kompetisie tussen die landbou, industriële en huishoudelike sektore vir water gebruike (Hamdy et al., 2003). Verhoogde voedsel produksie onder die kleinskaalse landbou sektor word gesien as moontlike oplossing vir die voedsel sekuriteit uitdagings in die platteland areas van die Limpopo Provinsie in Suid-Afrika (Altman et al., 2009). Kleinskaalse boere in Giyani gebruik meestal tradisionele voor-besproeiings stelsels en hul produktiwiteit bly steeds baie laag wanneer dit met kommersiële boerderye vergelyk word. Die hoofdoel van hierdie studie is om Water Produktiwiteit (WP) te bestudeer en verskeie innovasie tegnologieë te toets om beter besproeiing bestuur van kosbare water bronne te fasiliteer. Die studie was uitgevoer op twee plase, naamlik Zava Koöperatiewe Tuin en Mzilela Koöperatiewe Tuin, wat in die plattelandse areas van Giyani geleë is en die studie is gedoen oor ‘n periode van twee jaar vanaf 2012 tot 2013. Om hierdie doelwit te bereik was die navorsing in drie eenhede uitgevoer. Eerstens sal Naby-Infra Rooi (NIR) tegnologie gebruik word om die voorspelling vermoë van grond chemiese eienskappe te toets vir meer effektiewe grond voedingstof bestuur deur kleinboere. Tweedens sal WP proewe uitgevoer word op kleinskaalse tamatie (Solanum lycopersicum) produksie. Die huidige tamatie gewasproduksie stelsels was getoets om die WP statusse te evalueer van hul tradisionele bestuurs praktyke van beide drip- en voorbesproeiings stelsels. Laastens, is insette en uitsette van die kleinboere se produksie stelsels met die MonQI metodologie bestudeer om die huidige produksie sisteme te evalueer, sowel as die WP proef persele, deur opbrengs, grond voedingstof balanse en netto plaas inkomste (NPI) te moniteer en te bereken vir 4 half jaar seisoene gedurende die navorsings periode. Die resultate van die navorsing voer aan dat die gebruik van innovasie tegnologieë onder kleinskaalse boerderystelsels ontsettend belangrik is vir verbeterde produksie. Hoofbevindings van die NIR tegnologie dui dat meer doeltreffende grond voedingstof bestuur moontlik is en wat goedkoper en meer gebruikersvriendelik is vir kleinboere. Hierdie tegniek het goeie voorspelbaarheid-modelle getoon vir pH (KCl), Elektriese Geleiding (EG), P, K, Mg, Na en katioon uitruilings kapasiteit (KUK) met R2 en RPD waardes hoër as 0.60 en 1.4 onderskeidelik. Die voorspelbaarheid van Ca was minder suksesvol met ‘n R2 waarde van 0.43. Die resultate van die WP toetse wys dat drip besproeiing beter as voorbesproeiing presteer het in terme van opbrengs en WP. Opbrengs en WP was baie laag vir alle behandelings van seisoen 1, met waardes laer as 32 t/ha en 5.2 kg/m-3 onderskeidelik. Verbeterde bestuurspraktyke, soos grond voedingstof bestuur asook die gebruik van ‘n deklaag, was in die 2de en 3rde seisoen toegepas om opbrengs en WP te verhoog op plaasskaal op Mziela plaas. Resultate het gewys dat opbrengs verhoog het van ‘n gemiddelde van 26.5 t/ha tot 120.9 t/ha en WP verhoging van 4.61 kg/m-3 tot 17.69 kg/m-3. In terme van die insette en uitsette van die produksie sisteme het opbrengste van alle gewasse, wat nog van tradisionele metodes gebruik, laer as 5 t/ha getoon. Soms van die totale oeste verloor deur hael of hittegolwe. Die NPK balanse vir die gewasverbouing met konvensionele kleinboer metodes was in die orde van 0 tot -70 kg/ha. Die kunsmis behandelings van die tamatie proewe van die 1ste, 2de en 3rde WP seisoene het positiewe balanse getoon vir P en K in die orde van 80 tot 140 kg/ha. Die N balanse was meestal negatief vir alle verbouings persele. Die NPI was R2768 en R4740 vir seisoen 1 en 3 onderskeidelik, terwyl die 2de seisoen verlies van -R5176 getoon het. Die verbeteringe in opbrengs met die WP proewe en met die verkoop van die tamaties aan die Spar was die NPI vir die 4de seisoen R42486. Die studie sluit dat daar groot moontlikehede is vir verhoging in opbrengs, WP en NPI onder kleinboere in die Giyani area.

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