Variation of Temperature and Burning Time With Percntage of Potassium and Phosphorus in Rice Husk Ash used for Improving Crop Yields

Variation of Temperature and Burning Time With Percntage of Potassium and Phosphorus in Rice Husk Ash used for Improving Crop Yields

1Mbakaan, Celestine 2Aiji Ada Amedu, 3Baaki Emmanuel

1Department of Sience Laboratory Technology, Benue state polytechnic, Ugbokolo

2Department of physics, college of advance and professional studies, Makurdi.

3Department of mechanical Engineering Technology, Benue state polytechnic, Ugbokolo.

Abstract–Potassium and phosphorus are among the sixteen macronutrients needed for plant growth and high productivity. The two crop macronutrients are found in rice husk ash in a quantity usable to the crop. It is observed that the amount of potassium and phosphorus contain in rice husk ash varies with burning temperature and burning time. Inorder to investigate this fact, rice husk ash was produced at temperatures of 500oC, 600oC and 700oC at constant burning time of 4hours. In the second case, rice husk ash was produced at a constant temperature of 600oC for three different burning time of 2hours, 4hours and 6hours. The percentage of potassium and phosphorus in each case was determined by X-ray fluorescence analysis. Result shows that, the percentage of potassium and phosphorus in rice husk ash decreases as burning temperature and burning time of the husk increases.

Key words: Rice husk ash (RHA), potassium, phosphorus,time, temperature

1. INTRODUCTION

   In Benue state of Nigeria, farmers used rice husk ash for the cultivation of crops inorder to gain high crop yields (Celestine et al., 2013). Rice husk ash contain 0.72-3.84% K2O (Muthadhi et al., 2007). Bronzeoak Ltd (2003) found the percentage of potassium and phosphorus in rice husk as 0.10-2.54% K2O and 0.01-2.69% P2O5 respectively. However, it was also reported that rice husk ash have 5.4% P2O5 and 2.57% K2O (Onoja et al., 2013). Goncalvesa and Bergmannb (2006) found in their research a value of 3.65 K2O.

   The variation in the percentage values of potassium and phosphorus as observed in the result above could be due to variation in burning temperature, time and fertilizer application. In this research paper, variation of burning temperature and time on percentage of potassium and phosphorus in rice husk ash has been investigated. This research is based on the fact that potassium and phosphorus are macronutrients needed for the improvement of crop yields.

   Potassium and phosphorus are among the major sixteen essential nutrients needed in the soil for plant growth and high productivity (Marschner, 1995). The source of these nutrients could be organic or inorganic (Priyadharshini and Seran, 2009). Combining both organic and inorganic fertillizer in crop production result to improved soil fertility and high crop yield (Mamaril., 1999).

   Researchers have found that rice husk an agricultural organic waste is another source of major soil nutrients. Rice husk generates rice husk ash when burn in an open environment or at controlled temperature. The generated ash contain high grade amorphous silica (Mishra et al., 1986) as the major compoud. The ash also contain trace elements such as potassium and phosphorus.

2. MATERIALS AND METHODS

   Rice husk ash was collected from Aliade rice milling industry in Benue state Nigeria. The husk was sieved to remove broken particles and other impurities. It was then allowed to dry in an open environment for two days . The husk was then burn in the open environment to produce black ash. Air was blown to help ignite the husk since rice husk is very difficult to ignite. The black ash produced was allowed to cool naturally overnight. 60g of the black ash was produced and divided into 6 clean crucibles each containing 10g of the black ash. The crucibles were labelled A, B, C, D, E, and F. The black ash in A, B and C were burnt at temperatures of 500o C, 600oC and 700oC respectively for the same burning time of 4hours. The black ash in D, E and F were burn at a temperature of

   600oC for 2hours, 4hours and 6hours respectively. In each case cooling was done naturally. Carbolite furnace model GPC12/81+103 with temperature range of 0-1200oC was used to burn the black ash into white ash. The ash chemical composition was determined by using energy dispersive X- ray fluorescence spectrometry minipal 4 model © 2005 paanalytical B.V.

3. RESULT

   The percentage of potassium and phosphorus found by XRF measurement of rice husk ash is shown in table 1.1 and 1.2 below. The major compound found in each case was SiO2 while all other compounds were trace compounds.

   Table1.1: Percentage of Potassium and Phosphorus in RHA burn at 500oC, 600oC, 700oC for a constant time of 4hours.

   Compound	Temperatu re 500oC (A)	Temperature 500oC (B)	Temperature 600oC (C)
   K2O	2.58	1.98	1.01
   P2O5	5.41	4.23	2.82

   Table 1.2: Percentage of potassium and phosphorus in RHA burn at 600oC for 2hours, 4hours and 6hours.

   Compound	Time 2hours (D)	Time 4hours (E)	Time 6hours (F)
   K2O	2.57	2.00	1.00
   P2O5	5.47	4.24	2.800

4. DISCUSSIONS

   The result of chemical composition of rice husk ash by XRF shows that the ash contain several elements with SiO2 as the major compound while K2O and P2O5 are among the trace compounds found. However, the result in table 1.1 and table 1.2 shows the values for potassium and phosphorus only because it is where we have our major interest.

   The high percentage of K2O and P2O5 in all the samples is due to high fertilizer application and use of herbicides during growth of rice.

   In table 1.1, the result shows that the percentage of both potassium and phosphorus in rice husk ash decreases as temperature increases at constant burning time. In table 1.2, the result shows that the percentage of potassium and phosphorus decreases as burning time increases.

5. CONCLUSION

The percentage of potassium and phosphorus in rice husk ash decreases with increase in burning temperature and time. Therefore, low temperature and short burning time are recommended when rice husk ash is to be burn with the aim of obtaining high percentage values of potassium and phosphorus for application to improve crop yield.

REFERENCES

1. Bronzeoak Ltd (2003). Report of the rice husk ash market study. Bronzeoak Ltd, UK, pp: 62.

2. Celestine, M., Audu, O., Msughter, G., and Dooshima, T. (2013). Variation of some physical properties of rice husk ash refractory with temperature. International journal of science and research, India online.

3. Goncalvesa, M.R.F. and Bergmannb, C.P (2006). Thermal insulators made with rice husk ashes: production and correlation between properties and microstructure. Cont.build. meter, 21(12): 2059-2065

4. Mamaril, C., Gonzales, V., Olegario, A. and Obcmea, W. (1999). Integrated Plant nutrient management systems in the philippines: Review and analysis. The fertilizer advisory development information network for Asia and pacific (FiDINAP). Bangkok Thailand, pp: 117.

5. Marschner, H. (1995). Mineral nutrition of higher plants.Second edition

   academic press London. Pp:889.

6. Muthadhi, M., Anitha, R. and Kothandaramann (2007). Rice husk ash properties and its uses a review. Journal of the institution of Engineers (india) 88, pp: 50-55.

7. Onojah, A.D., Agbendeh, N.A and Mbakaan, C. (2013). Rice husk ash refractory: the temperature dependent crystalline phase aspects. International Journal of research and reviews in applied sciences (IJRRAS). Pp:247.

8. Priyadharshini, J. and Seran, T.H. (2009). Paddy husk ash as a source of potassium for growth and yield of cowpea (vigna unguiculata L). The Journal of Agricultural sciences. Department of crop science, Faculty of Agriculture, Eastern university Sri Lanka.