Raafat N. Zaki and Habashy R. Nader( 2011). Effect of applied different nitrogen sources and some bio-organo-stimulants on sweet pepper plants grown on a saline calcareous soilFayoum J. Agric. Res. & Dev., Vol.25, No.1, January, 2011
Abstract: A field experiment was carried out on a saline calcareous soil cultivated with sweet pepper plants (Capsicum annuum L.) under drip irrigation system at a private farm, Nubaria region, El Beheira Governorate, Egypt during two successive seasons 2009 and 2010. The aim target of the current study was identified the effect of soil application for different N-source of (ammonium nitrate, calcium nitrate and ammonium sulfate) as solely treatments or in combination with some bio-organo-stimulants (potassium humate, potassium citrate or yeast) on the plant growth parameters, nutritional status, fruit yield and its quality as expressed by titratable acidity, total soluble solids, total carbohydrates, vitamin C, anthocyanin, total polyphenols, and mineral contents (Ca and K), fruit nitrate, with a special reference to the associated effects on the soil properties and available nutrient contents. The mineral N, P and K fertilizers in their different forms were applied as the recommended rates after Ministry of Agriculture, i.e., 100 kg N fed-1, 48 kg K2O fed-1 and 15.5 kg P2O5 fed-1, while potassium humate at 0.5 g L-1, potassium citrate at 1.0 g L-1 and yeast at 2 g L-1, which added at the same time of applied nitrogen sources through the drip irrigation system. Taking into consideration K-amount of (K-humate+K-citrate) represents 25% of the applied recommended K-rate.
The obtained results indicated that there were significantly increases in soil organic matter and available nutrients contents as a result of applied different N-sources and bio-organo-stimulants, with a superiority effect for the combined treatment of (ammonium nitrate+ K-humate). On the other hand, soil pH and ECe were took place a parallel opposite trend, where their values exhibited significantly decreases, with a superiority effect for the previous combined treatment. It is noteworthy to mention that, it could be categorized the applied treatments according to their superiority effects on the studied soil properties into two ascending orders: Am-Ni > Am-Su > Ca-Ni and K-Hu > K-Ci > Ye as solely treatments of N-sources and bio-organo-stimulants, respectively. The second order: (Am-Ni+K-Hu) > (Am-Ni+K-Ci) > (Am-Ni+Ye), (Am-Su+K-Hu) > (Am-Su+K-Ci) > (Am-Su+Ye) and (Ca-Ni+K-Hu) > (Ca-Ni+K-Ci) > (Ca-Ni+Ye) as the applied combined treatments.
As for plant parameters of sweet pepper, the data showed that the effective role of the applied treatments on leaf number/plant, branch number/plant, plant height, leaves weight/plant and nutritional status as well as fruit yield and its quality parameters behaved a similar parallel trend as was achieved with the studied soil properties. That was true, since the achieved favourable amelioration in soil properties was positively effected on the plant growth parameters, fruit yield and its quality. Moreover, such findings are confirmed by the best effective role of the combined treatment (ammonium nitrate+ K-humate) that was also achieved the greatest values in plant growth parameters as well as fruit yield and quality of sweet pepper.
Keywords: (Sweet pepper, N-sources, Bio-organo-stimulants (K-citrate, K-humate and yeast), saline calcareous soil, drip irrigation system. )
