Root-induced Changes in the Rhizosphere of Extreme High Yield Tropical Rice: 2. Soil Solution Chemical Properties

Our previous studies showed that the extreme high yield tropical rice (Padi Panjang) produced 3-8 t ha-1 without fertilizers. We also found that the rice yield did not correlate with some soil properties. We thought that it may be due to ability of root in affecting soil properties in the root zone. Therefore, we studied the extent of rice root in affecting the chemical properties of soil solution surrounding the root zone. A homemade rhizobox (14x10x12 cm) was used in this experiment. The rhizobox was vertically segmented 2 cm interval using nylon cloth that could be penetrated neither root nor mycorrhiza, but, soil solution was freely passing the cloth. Three soils of different origins (Kuin, Bunipah and Guntung Papuyu) were used. The segment in the center was sown with 20 seeds of either Padi Panjang or IR64 rice varieties. After emerging, 10 seedlings were maintained for 5 weeks. At 4 weeks after sowing, some chemical properties of the soil solution were determined. These were ammonium (NH4+), nitrate (NO3-), phosphorus (P) and iron (Fe2+) concentrations and pH, electric conductivity (EC) and oxidation reduction potential (ORP). In general, the plant root changed solution chemical properties both in- and outside the soil rhizosphere. The patterns of changes were affected by the properties of soil origins. The release of exudates and change in ORP may have been responsible for the changes soil solution chemical properties.Keywords: Ammonium, electrical conductivity, iron, nitrate, oxidation reduction potential, pH, phosphorus [How to Cite: Purnomo E, D Choiron, R Yulia, H Halim, Krisdianto, A Hairani and M Osaki. 2012. Adding Organic Matter Enhanced the Effectiveness of Silicate Rock Fertilizer for Food Crops Grown on Nutritionally Root-induced Changes in the Rhizosphere of Extreme High Yield Tropical Rice: 2. Soil Solution Chemical Properties. J Trop Soils, 17 (3): 67-74. doi: 10.5400/jts.2012.17.3.189][Permalink/DOI: www.dx.doi.org/10.5400/jts.2012.17.3.189

Root-induced Changes in the Rhizosphere of Extreme High Yield Tropical Rice: 1. Soil Chemical Properties

Root-induced Changes in the Rhizosphere of Extreme High Yield Tropical Rice: 1. Soil Chemical Properties     (E Purnomo,  M Turjaman, A Hairani, A Mursyid, D Choiron, R Yulia and M Osaki): Padi Panjang cultivar is one of many local rice cultivars found in South Kalimantan that yields 8 Mg ha-1 without fertilizer after last transplanting. The mechanisms involved in sustaining nutrient supply to sustain the extreme high yield are of interest. The following work aims to investigate the changes of soil chemical properties in rizhosphere of Padi Panjang cultivar. The Padi Panjang cultivar was grown in a rhizobox filled with soils from 3 different villages in Banjar Regency, South Kalimantan Province, namely, Kuin, Bunipah and Guntung Papuyu. The rice plant was grown for 5 weeks. At the end of the growing period, soil chemical properties such as pH, aluminum (Al), phosphorus (P), potassium (K+), ammonium (NH4+), and nitrate (NO3-) were measured. The results showed that Padi Panjang cultivar had the capability to change the soil chemical properties in the rhizophere. The impact was more extent compared with IR64 cultivar. The changes were depended on soil character, especially, soil texture. The soil from Guntung Papuyu was the least affected by root. It was observed that Padi Panjang cultivar acidified more than IR64. A depletion zone of K+ and NH4+ was found in the rhizosphere of both Padi Panjang and IR64 cultivars. The depletion zone of these ions could reach as far as 3 cm from the rhizosphere. For P, the depletion zone only occurred in the rhizosphere soil of IR64 cultivar. However, for Padi Panjang cultivar, the depletion zone of P did not exist. The Padi Panjang cultivar was able to maintain P concentration the same as or higher than control soil without plant. This is the first report showing that Padi Panjang cultivar can be considered as efficient lowland rice cultivar in absorbing not only P but also K in a P- and K-deficient-soil

Root-induced Changes in the Rhizosphere of Extreme High Yield Tropical Rice: 2. Soil Solution Chemical Properties

Our previous studies showed that the extreme high yield tropical rice (Padi Panjang) produced 3-8 t ha-1 without fertilizers. We also found that the rice yield did not correlate with some soil properties. We thought that it may be due to ability of root in affecting soil properties in the root zone. Therefore, we studied the extent of rice root in affecting the chemical properties of soil solution surrounding the root zone. A homemade rhizobox (14x10x12 cm) was used in this experiment. The rhizobox was vertically segmented 2 cm interval using nylon cloth that could be penetrated neither root nor mycorrhiza, but, soil solution was freely passing the cloth. Three soils of different origins (Kuin, Bunipah and Guntung Papuyu) were used. The segment in the center was sown with 20 seeds of either Padi Panjang or IR64 rice varieties. After emerging, 10 seedlings were maintained for 5 weeks. At 4 weeks after sowing, some chemical properties of the soil solution were determined. These were ammonium (NH4+), nitrate (NO3-), phosphorus (P) and iron (Fe2+) concentrations and pH, electric conductivity (EC) and oxidation reduction potential (ORP). In general, the plant root changed solution chemical properties both in- and outside the soil rhizosphere. The patterns of changes were affected by the properties of soil origins. The release of exudates and change in ORP may have been responsible for the changes soil solution chemical properties

Root-induced Changes in the Rhizosphere of Extreme High Yield Tropical Rice: 1. Soil Chemical Properties

Padi Panjang cultivar isone of many local rice cultivars found in South Kalimantan that yields 8 Mg ha-1 without fertilizer after last transplanting.The mechanisms involved in sustaining nutrient supply to sustain the extreme high yield are of interest. The followingwork aims to investigate the changes of soil chemical properties in rizhosphere of Padi Panjang cultivar. The PadiPanjang cultivar was grown in a rhizobox filled with soils from 3 different villages in Banjar Regency, South KalimantanProvince, namely, Kuin, Bunipah and Guntung Papuyu. The rice plant was grown for 5 weeks. At the end of thegrowing period, soil chemical properties such as pH, aluminum (Al), phosphorus (P), potassium (K+), ammonium(NH4+), and nitrate (NO3-) were measured. The results showed that Padi Panjang cultivar had the capability to changethe soil chemical properties in the rhizophere. The impact was more extent compared with IR64 cultivar. The changeswere depended on soil character, especially, soil texture. The soil from Guntung Papuyu was the least affected byroot. It was observed that Padi Panjang cultivar acidified more than IR64. A depletion zone of K+ and NH4+ was foundin the rhizosphere of both Padi Panjang and IR64 cultivars. The depletion zone of these ions could reach as far as 3cm from the rhizosphere. For P, the depletion zone only occurred in the rhizosphere soil of IR64 cultivar. However,for Padi Panjang cultivar, the depletion zone of P did not exist. The Padi Panjang cultivar was able to maintain P concentrationthe same as or higher than control soil without plant. This is the first report showing that Padi Panjang cultivar can beconsidered as efficient lowland rice cultivar in absorbing not only P but also K in a P- and K-deficient-soi