AGRICULTURAL RESEARCH COMMUNICATION CENTRE www.arccjournals.com/www.legumeresearch.in *Corresponding author’s e-mail: macilpatty@gmail.com 1 Department of Plant Production, University of Venda, Private Bag X5050, Thohoyandou, 0950, South Africa. 2 Department of Soil Science, University of Venda, Private Bag X5050, Thohoyandou, 0950, South Africa. Legume Research, 40 (2) 2017 : 299-305 Print ISSN:0250-5371 / Online ISSN:0976-0571 The response of some physiological traits of chickpea (Cicer arietinum L.) to biochar and phosphorus fertilizer application Patricia Jozina Macil 1 , John Bob Ochanda Ogola 1* , Jude Julius Owuor Odhiambo 2 and Siphiwe Gloria Lusiba 2 Department of Plant Production, University of Venda, Private Bag X5050, Thohoyandou, 0950, South Africa. Received: 07-06-2016 Accepted: 05-11-2016 DOI:10.18805/lr.v0i0.7290 ABSTRACT This study assessed the response of photosynthesis, chlorophyll content (CC), stomatal conductance (SC) and intercepted radiation (IR) of chickpea to biochar (0, 5 10 and 20 t ha -1 ) and phosphorus (P) fertilizer (0 and 90 kg ha -1 ) rates in Thohoyandou, South Africa in 2013/2014 summer and winter seasons. Photosynthesis, CC, SC and IR were determined at vegetative and reproductive stages. Biochar increased SC and CC by 22 - 49% and 57 – 126%, respectively. P increased CC by up to 9% in the winter sowing. IR increased with P and biochar application in both sowings. Biochar increased plant height only at 70 days after emergence and P increased plant height at all plant growth stages. Biochar and phosphorus did not affect photosynthesis in either season. Therefore the use of biochar and inorganic phosphorus fertilizer may be beneficial in chickpea cropping systems characterised by poor soils and dry winter seasons. Key words: Chlorophyll content, Growth, Intercepted radiation, Stomatal conductance. INTRODUCTION In the continuous cropping systems of the semi- arid areas of North East South Africa, cultivation of crops is carried out throughout the year with minimal addition of external inputs, if any, leading to incessant depletion of soil fertility. To avert further soil fertility depletion in these areas and sustain crop productivity, management practices should be geared towards improving and maintaining soil fertility. The use of soil amendments (e.g. biochar), organic and inorganic fertilizers, and suitable crop genotypes may ameliorate the soil fertility problem and lead to improved and sustainable crop productivity. Biochar is defined as charcoal obtained when organic materials are burned under low pressure and high temperature condition through pyrolysis process under low or absence of oxygen (Lehmann 2007). Moreover, incorporation of drought tolerant legumes such as chickpea ( Cicer arietinum L.) may increase productivity and minimize crop failure risks of current cropping systems in dry environments and thus play a significant role in achieving sustainable food security. Chickpea may contribute to agricultural sustainability through nitrogen (N) fixation and as a rotation crop. Symbiotic N fixation can produce greater than 100 kg N ha -1 (Beck 1992), and provide up to 85% of the N required by a chickpea crop (Walley et al. 2005; Chemning’wa and Vessey 2006). According to Sinclair and Vadez (2002), phosphorus (P) is required for N fixation by legumes and thus improving P management is crucial in enhancing legume production. Thus, P may influence chickpea productivity indirectly by improving the soil N status. The effect of P fertilizer on yield and yield components of chickpea is well documented (Madzivhandila et al. 2012; Turuko et al. 2014). However, there is a dearth of information in literature on the interactive effect of biochar and phosphorus on chickpea productivity especially in dry environments. Most documented studies on the combined effect of P and biochar on chickpea productivity were conducted in pots (Budania and Yadav 2014) and it is likely that the field response may vary. Therefore this study aimed at assessing the response of photosynthesis, chlorophyll content, stomatal conductance and intercepted radiation of chickpea to biochar and phosphorus in one representative location of dry environments in NE South Africa. MATERIALS AND METHODS Experimental site: Two field experiments were conducted in Thohoyandou (22 o 58.08´S and 30 o 26.4´E, and 595m above sea level), NE South Africa. The area receives an annual rainfall of ± 500 mm that falls predominantly in summer. The average maximum and minimum temperatures are 31 and 18 ° C, respectively (Tadross et al. 2006). The site is characterized by deep, well-drained clay soils (Soil Classification Working Group 1991). Soil analysis prior to