Concentration Of. Nitrogen And Heavy. Metals In A Typic. Haphstult In Abakaliki. Nigeria And Yield. Characteristics Of. Maize As Influenced By

Transcription

1 Concentration Of Nitrogen And Heavy Metals In A Typic Haphstult In Abakaliki Nigeria And Yield Characteristics Of Maize As Influenced By Inorganic Fertilizer Ekpe I.I Department of Soil Science and Technology, School of Agriculture and Agricultural Technology, Federal University of technology, P.M.B 526,Owerri, Nigeria E.N.Ogbodo Department of soil and Environmental Management, Faculty of Agriculture and Natural Resource Management, Ebonyi State University, P.M.B 053,48000,Abakaliki, Nigeria M.O Nwaigwe Department of Crop Production Technology, Federal College of Agriculture, Ishiagu, Ebonyi State O.C. Olejeme Department of Agricultural Science and Vocational science, Alvan Ikoku College of Education, PMB 033, Owerri

2 2 ABSTRACT An experiment was set up to investigate the effect of different levels of NPK 20; 0; 0 on the concentration of nitrogen and heavy metals in a typic haphstult in Abakaliki and yield characteristics of maize as influenced by inorganic fertilizer. The experiment was conducted at the Teaching and Research Farm of the Faculty of Agriculture and Natural Resources Management, Ebonyi State University, Nigeria. The treatments comprised of four levels of fertilizer rates (0 kg.ha -, 750 kg.ha -,500 kg.ha - and 2000 kg.ha - ) represented as T,T2,T3, and T4 respectively. The experiment was replicated five times and Oba 98 was used as test crop. Each the experimental plot measured 3 X 3 meter and the planting distance was 50 by 25cm 2 and two seeds per hole was planted and the total plant population was adjusted to give a total of 6,000 plants per hectare. The experiment was laid out in a randomized complete block design. Some selected heavy metals such as boron, manganese, zinc, lead, molybdenum, iron, the plant growth parameters that were determined at 70 days after planting (DAP) were plant height, stem diameter, shoot dry matter yield. After the data analysis, the results revealed that the soil percent nitrogen and heavy metal concentrations and crop growth parameters differed significantly when the control treatment was compared with the treatment and when the treatments where compared with one another. The results on manganese concentration did not show any significant difference between treatment and control and within treatments. The results strongly support wise use of organic fertilizer for improved maize crop growth and availability of useful heavy metals for improved food quality in Abakaliki. Keywords: Abakaliki, concentration, Fertilizers, Inorganic, Metals, Oba 98, Southeast. INTRODUCTION Long period of crop production without the incorporation of plant nutrients can adversely impoverish the soil. In Nigeria fallow periods were they exist has been reduced to less than 3 years in many farming villages. This is mainly due to urbanization. This very reduced period is far from being adequate in restoring the native fertility of the soil (Enwezor et. al.). Most soils in Abakaliki are low in effective cation exchange capacity (ECEC) (Ekpe, 203). Fertilization will be required to improve on the soil chemical properties and therefore maintain adequate crop production level to feed the ever increasing world population. The use of fertilizer will extend the productive life of the soil (Brady and weils,202) and sustain yield for the future generation.determining the levels for fertilizer application is scientifically necessary as it will avert the pollution effects of the abuse of its use. Soils and crops are very variable in their response to fertilizer types that considerable care needs to be taken when it needs to be used (FAO, 976). Expert advice based on scientific results is required before the use of fertilizers as wrong use will definitely have negative effect in the soil, plants and the economy of the farmer and will lead to excessive release of heavy metals to the environment.

3 3 Maize is a very important crop in Nigeria. It has been found to act as a vegetable when eaten green and as grain when harvested dry. It has also found usefulness in many kitchen applications such as corn flakes, pap, pop corn, infant formulas, and corn four(ekpe,204). Oba 98 is a high yielding maize variety with high adaptability. It has been found to survive in an ultisol in Abakaliki (Ekpe 200). It is relatively high in protein and human and animal body welfare minerals. It is early maturing and resistant to draught. The above good attributes of Oba 98 justifies its use as a test crop in an experiment to determine the concentration of nitrogen and heavy metals in a typic haphstult in Abakaliki and yield characteristics of maize as influenced by inorganic fertilizer 2. MATERIALS AND METHODS Experimental Site The experiment was conducted at the Teaching and Research Farm of the Faculty of Agriculture and Natural Resources Management, Ebonyi State University, Abakaliki. The area is located within latitude O6 0 N and longitude O8 0 56E in the derived savannah of the South-East agro-ecological zone of Nigeria. The rainfall pattern of the area is bimodal (April-July and September-November) with short spell in august. The total mean annual rainfall during the period ranged from 800mm to 2000mm. The mean annual temperature range was C during rainy season and the relative humidity was between 60-80% (EBADEP, 2009). The soil type is sandy clay loams which in some areas are poorly drained. The soil is hydromorphic and belongs to the order ultisol under the Ezzamgbo soil association derived from shale and classified as Typic Haphstult (FDALR, 985; Ofomata, 975). Materials The materials used were: maize variety Oba 98 and NPK 20:0:0 fertilizer, purchased from Ebonyi State Agricultural Development Programme (EBADEP). Land Preparation/Experimental Design/Layout The experimental site was cleared of existing vegetation manually using cutlass. Debris was removed. The site was mapped out using tape, ropes and pegs. The area of site used was 9.0m x 3.5m (0.0256ha). The land area was demarcated into blocks and each block was further divided into plots. Each plot measured 3 X 3 m 2. The blocks were separated from each other by m alley and each plot was separated from the other by another m. The experiment was laid out in Randomized Complete Block Design (RCBD) with 4 treatments. The treatments were replicated five times to give a total of 20(twenty) plots. The application rate of fertilizer as

4 4 treatment was at 0 kg.ha -,750 kg.ha kg.ha - and 2000 kg.ha - NPK 20:0:0 as T,T2,T3 and T4 respectively. Planting of Test Crop and Treatment Combination Maize variety Oba 98 was planted 4 seeds per hole at a planting distance of 50 x 25cm between and within rows respectively. After two weeks of germination, the plants were thinned down to 2 seedlings per stand to give a plant population of 6000 stands per hectare. Weeding was done as often as the need arose. Harvesting was done at maturity of the crop which was determined by the turning of the husks to brown. Soil Sampling and Analysis Twenty soil samples were collected randomly from 0-30cm soil depths within the field and analyzed for initial soil properties before treatment application. Again other sets of soil samples were collected from each of the experimental units after harvesting.. The samples were collected with soil auger attached with a core sampler. The soil samples from each plot were bulked; thoroughly mixed, ground to pass through a 2mm sieve and representative samples collected for heavy metals determination. One gram of each of the sieved soil sample was digested using the nitric perchloric acid digestion procedure. The concentrations of the selected heavy metals were determined using atomic absorption spectrophotometer (Unicam Solar 32 model) following the standard procedures of AOAC(990) The ratings for adequacy or otherwise of concentrations was according to Landon, (99).Total nitrogen was determined by the modified micro Kjeldahl distillation methods (Bremner,993). Agronomic Data All agronomic parameters were determined at 70 days after planting (DAP) except the grain yield and these parameters were; Plant Height Five plant stands from each net plot were randomly selected and measured for plant height. Plants height was determined using a calibrated metric rule and was done at 70 days after planting (DAP) from the soil base to the tip of the longest leaf blade. Stem Diameter This was determined at 70 days after planting (DAP) by the use of a measuring tape. Stover Yield This was measured by weighing the stock of the whole plant after removing the cob. The result was recorded in t.ha -.

5 5 Data Analysis Statistical analysis of data was done based on the procedure outlined by Gomez and Gomez (986) for randomized complete block design(rcbd).separation of treatment means for significant effect was done by the use of Fishers least Significant Difference (F-LSD). 3. RESULTS AND DISCUSSION The pre-tillage soil sample results should that the soil of the area is low in heavy metal concentration. Iron, boron, manganese and molybdenum are rated deficient, while iron is rated sufficient (Tables and 3). The results of the effect of fertilizer rates on soil nitrogen and heavy metal concentrations are presented in Table 2. parameter % N Table : Soil Chemical Properties before the experiment Fe Pb B Mo Mn Cu Values Percent Nitrogen There was a trend in the nitrogen concentration along the line of treatment. The highest application rate (2000 kg.ha - ) recorded the highest concentration. There were 0.04, 0.08 and 0.23% higher concentration of nitrogen in soils treated with 750, 500 and 2000 kg.ha - when compared with 0 kg.ha - treatment rate. Also there were increase in soil nitrogen of 0.04 and 0.9 %when 500 and 2000 kg.ha - treatment rates were compared with 750 kg.ha - application rate respectively. Table 2: Effect of Fertilizer Rates of Some Selected Chemical Properties Treatments % N Fe B Mo Mn Cu O kg.ha a 5.28 a 0.89 a 0.95a 37.6 a 4.34 a 750 kg.ha b 5.62 b.07 b.38b 36.5 a 5.58 b 500 kg.ha c 5.06 a.29 c.59 c 40.8 a 4.96 c 2000 kg.ha d 2.78 c 0.95 d 0.60 d 37. a 2.40 d FLSD(P=0.05) NS 0.30 Note: Figures with the same superscripts are not statistically significant The 2000 kg.ha - application rate recorded 0.5% more nitrogen than soils treated with 500 kg.ha -. The application of 750, 500 and 2000 Kg.ha - NPK 20:0:0 was able to raise the soil nitrogen from very low rating to medium rating (Table 3). Nitrogen is a very important nutrient in cereal production. The higher application rates may invariable release more nitrogen to the soil. High concentration of nitrogen in the soil can leach into ground water and surface water bodies. In surface water it can cause enthrophication and in drinking water can lead to blue babe syndrome in infants.

6 6 Iron There was significant difference in the iron concentration of the control treatment when compared with those of the treatment and when the results of some of the treatments were compared with one another but there was no significant difference in soil iron concentration when the control was compared with 500 Kg.ha - and when 750 Kg.ha - application rate was compared with500 Kg.ha -. Among the statistically significant comparism 750 Kg.ha - application rate recorded 0.34 more iron than the control. %Nitrogen Table 3: Rating of percent soil nitrogen (%N) Rating > -.0 Very high High Medium Low < - 0. Very low Adopted from Landon 99 Also there was hug concentration of 2.5 and 2.48 Cmol.kg - more iron in soils treated with 2000 Kg.ha - when it was compared with iron concentration from 0 and 750 Kg.ha - respectively. As the soil ph values reduced towards acidic condition, the heavy metal dissolution increased, thereby increasing their concentration in soil water. This explains the significant increase in the concentration of the element as treatment rates increased. The concentration of iron in the soil before and after the treatments were imposed on the soil was within permissible limits (Table 4). Iron is a very important element in hemoglobin formation in red blooded animals. Its presence in soil in adequate amount can improve on the nutritional quality of a crop plant. BORON (B) The concentration of boron increased as the rate of application increased up to 500 Kg.ha -. But after that the concentration dropped. There was 0.8, 0.4 and 0.06 more boron in the soils treated with 750, 500 and 2000 Kg.ha - application rates when compared with the control treatment. Micronutrients Table 4: Ratings of micronutrients in the soil Concentrations in the soil Deficient Sufficient Excessive B < >200 Cu Fe Mn < 4 < 50 < > 20 > 250 > 500

7 7 Mo Zn <. 0 < 20 Adopted from Landon >.0 > 400 A comparism of 750 Kg.ha - treated soil with 500 and 2000 Kg.ha - treatment rates revealed respectively 0.22 and o.2 higher concentration of boron in the soil. Also when 500 Kg.ha - was compared with 2000 Kg.ha - increase of 0.34 in favour of the former was recorded. Boron is deficient in these soils (Table 4). Boron is present in the rock mineral, turmaline, from which it is weathered to form plant available borate (BO 3 3- ). Boron accumulates in organic matter, and is freely available to plants in all except alkaline soils. Over liming can induce boron deficiency. Boronated fertilizers can be used to overcome these problems when growing Boron demanding crops (Reid and Parkinson98) Molybdenum The results of the effect of the different rates of fertilizer application (Table 2) revealed that there was significant difference when the control was compared with the treatments and when the treatments were compared with one another. There were 0.43, 0.06 Cmol.Kg. - more molybdenum in soils treated with 750 and 500 Kg.ha - than t in the soils from the control plots respectively. But there was a reduction in the concentration molybdenum down to 0.35 when the control was compared with 2000 Kg.ha -. Also there was 0.2 and 0.78 more Mo in the soils treated with 500 and 2000 Kg.ha - than in the soil treated with 750 Kg.ha -. The result revealed 0.99 Cmol.kg - higher mean difference of Mo when 500 Kg.ha - was compared with 2000 Kg.ha -. The Mo concentration before the experiment revealed sufficient quantities in the soil. This chemical balance was disrupted when organic fertilizer was applied to the soil (Table 4). Manganese The result of the effect of fertilizer rates on soil manganese, revealed that the there was.7, 3.6 and 0.50 Cmol.Kg. - more Mn in the soils treated with 750, 500 and 2000 Kg.ha - respectively when compared with Mn concentration from the soil of the control plot. There was 4.33 and 0.67 more Mn from the soil that received 500 and 2000 Kg.ha - NPK 20:0:0 than the soil that received 750 Kg.ha - application rates. Again there was 3.4 more Mn in soils treated with 500 Kg.ha - than in the soil that received 2000 Kg.ha -. Generally the soil contained adequate quantities of Mn before and after the experiment (Table 4). Manganese is abundant in most soils, being weathered from rock minerals to form the plant available Mn 2+ ion, which is retained on the exchange complex. Alkaline and freely drained soils can be deficient in plant available Mn, while very acid soils and those that are poorly drained can contain high concentrations of Mn that may be toxic to plants. Cupper (Cu)

8 8 There was statistically significant difference in the cupper concentration of the soil when the treatments were compared with the control and when the treatments were compared with one another. The application of the nitrogen fertilizer improved the cupper concentration in the soils that received different rates except 2000 Kg.ha -. At this rate the concentration cupper in the soil reduced by 2.56 when compared with 500 Kg.ha - application rate. There was general improvement up to.24, 0.62 and.9 in the soils treated with 750, 500 and 2000 Kg.ha - when compared with the control rates respectively. Within the treatment rates, 500 Kg.ha - application rate recorded 0.62 Cmol.kg - more than 750 Kg.ha - while there was 3.8 Cmol.ha - more cupper in the 750 Kg.ha - treated soils than in the soils that received 2000 Kg.ha -. In all only 750 Kg.ha - application rates raised cupper concentration up to marginal sufficiency level (Table 4). The other cupper values recorded from the control through the rest of the treatments were too low and therefore is said to be deficient as can be seen from table 4. Copper is released from rock mineral by weathering and it is held on the exchange complex. Copper availability, decreases with increasing ph, hence alkaline, sandy or mineral poor organic soils may be Copper deficient. Cu deficiency may be overcome by the application of copper sulphate (Webster and Wilson980). Effect of Fertilizer Rates on Pant Height, Stem diameter, and Stover Yield Of Oba 98 Effect NPK 20:0:0 on Oba 98 plant height, stem diameter and stover yield are presented in table 5. PLANT HEIGHT There were positive variations in the maize height when plants from the control were compared with those from the treatments and when those from the treatments were compared with one another. The highest height difference of 0.4 cm was recorded when plant from the control plot was compared with plants from plots treated with 2000 Kg.ha -. Table 5: Effect of Fertilizer Rates on Plant Height, Stem Diameter and Stover Yield at 70DAP Treatment Plant Height (cm) Stem Diameter(cm) Stover Yield Kg.ha - O kg.ha a 2.3 a 22 a 750 kg.ha b 2.94 b 360 b 500 kg.ha c 3.9 c 386 c 2000 kg.ha d 4.04 d 420 d FLSD(P=0.05) Note: Figures with the same superscripts are not statistically significant The fertilizer treatments significantly increased maize height by 4.3 and 72.8 cm when 750 and 500 Kg.ha - were compared with plants from the control plots respectively. Within the treatments they were also significant increases along the increasing rate of application. There were 3.5 and 60.cm increase in height when plants from 750 Kg.ha - were compared with plants height from plots treated with 500 and 2000

9 9 Kg.ha - NPK 20:0:0 respectively. There was also 28.5 cm taller plants from the plots treated with 2000 Kg.ha - application rate relative to plants grown on plots that received 500 Kg.ha -. Maize is a high consumer of nitrogen fertilizer. The increasing height of the plants along increasing rates of application would have resulted from improved metabolic activity of the maize plant as a result of improve nutrition during the vegetative phase of the plant (Brady,202). STEM DIAMETER The diameter of the stem diameter represents the resistance of the plant to resist lodging. The treatments improved the thickness of the plants stem when the plants from the control plots were compared with plants from the plots treated with 750, 500 and 2000 Kg.ha - rates of application and when these application rates (750, 500 and 2000 Kg.ha - ) were compared with one another. Plots that received 750,500 and 2000 Kg.ha - treatments produced plants with 0.8,.06 and.8 cm thicker stem than plants that were grown on plots that received 0 Kg.ha - NPK 20:0:0 application rate. Also there were 0.25 and.cm thicker plants from plots treated with 500 and 2000 Kg.ha - when compared with maize plant produced from plots that were fertilized with NPK 20:0:0 at 750 Kg.ha - application rates. As a result of the increasing effect of the increasing rate of NPK 20:0:0, there was also 0.85 cm increase in thickness in the plants that were grown on plots that received 2000 Kg.ha - relative to the maize plants were produced from the plots that received 500 Kg.ha - of NPK 20:0:0. Nutrient balanced in soils ensure high structural strength in the presence of adequate potassium supply to the soil. The fertilizer application rates up to 2000 Kg.ha - to the Oba 98 has proved to be very useful in its production. STOVER YIELD There was statistical significant difference in the stover yield of Oba 98 when yield from the control was compared with yield from the treatments and when results from the treatments were compared with one another. There were 48, 74 and 208 Kg.ha - increase in stover yield from the plots fertilized with 750, 500 and 2000 Kg.ha - of NPK 20:0:0 when compared with yield from the plots that received 0 Kg.ha - application rates. There were also 26 and 60 Kg.ha - recorded increase from plots that was treated with 500 and 2000 Kg.ha - rate of application when compared with stover yield from plots that received 750 Kg.ha - application rates respectively. There were also 34 Kg.ha - increases in stover yield from plots that received 2000 Kg.ha - when compared with the stover yield recorded from the plots that was fertilized at the rate of 500 Kg.ha -. Stover yield may be proportional to fertilizer rates. Increase in fertilizer rate would lead to increase in stover yield all things being equal.

10 0 4. CONCLUSION The use of NPK in fertilizing the soil for Oba 98 production had induced effect in micronutrient availability. The use of the fertilizer up to 2000 Kg.ha - improved the availability of most of the micronutrients studied. The results revealed that there was a great potential in NPK 20:0:0 improving the yield of Oba 98 maize yield at 2000 Kg.ha -. This rate of application is recommended for maize production particularly in the study area. 5. REFERENCES ASSOCIATION of ANALYTICAL CHEMISTS (AOAC).990. Laboratory Procedures for Water Analysis. p34. Brady,N.C.,Weil,R.R.202.The Nature and Properties of Soils. Twelfth edition. Prentice Hall. Inc. Simon 7Schnster A Viacon company, Upper Saddle River,New Jersey 80pp. Bremner, J.M. 965 Organic N. In: soil Nitrogen. Bertholome. W.W and Clark, F.E. (Eds) Am. Soc. Agron. Madison Wisconsin p.84. Ebonyi State Agricultural Development Programme (EBADP) 2009 Annual Report. pp. 45. Eifefiyi EK., Remision SU (2009). The Effects of Inorganic fertilizer on the yield of two varieties of cucumber (Cucumis sativus) Report and opinion: (5) Ekpe I.I. (203) Effect of Fresh Rumen Digesta on Soil Chemical Properties and Yield of Cucumber (Cucumis Sativus) in Abakaliki Southeast Nigeria. AJB Ekpe Ekpe I.I.(200) Changes in chemical properties of an Acid soil Amended with Agricultural Wastes and the Yield of (BAMBARA GROUNDNUT) Eznwezor WO, Udo EJ, Usoro NJ,Ajotade KA (989). Fertilizer use, procurement and distribution (EPDD) (989): fertilizer use and management practices for crops in Nigeria. F.A.O (976). Organic materials as fertilizers, soils bulletin 27 F.A.O Rome. FDALR (985): Federal Department of Agriculture and Land Resources. Reconnaissance Soil Survey of Anambra State Nigeria Soils reports FDALR, Kaduna. Landon, J. R. (ed.) 99 Booker Tropical soil manual: A Hand Book for Soil Survey and Agricultural land Graduation in the Tropics and Subtropics. Book Tate, New York p Maclean EO (982): Soil ph and Line requirements. In: Page et al; (ends) Methods of soil Analysis part II. Am. Soc. Agron. 9 Madison WIUSA pp. Mbagwu JSC (992): Improving the productivity of a degraded ultisols in Nigeria using organic and inorganic amendments. Part 2: chemical properties and maize yield Biores. Technol 42: Mbah CN, Anikwe MAN, Onweremmadu EU, Mgbagwu JSC (2007). Soil organic matter and carbohydrate contents of a district leptosol under organic waste management and their roles in structural stability of soil aggregates Int. J. Soil Sci. 2: NRCS(998). Soil quality indicators: ph, soil Quality information sheet. Oformata GEK (975): Nigeria in Maps, Eastern States of Nigeria. Ethiopia publishing Houses, Midwest, Benin City 6pp. Reid, I & Parkinson, R.J 98. Too Wet, Too-Dry Clay Soil Problems. Soil and Water, Steel GD,Torrie JH, (980). Principles and Procedures of statistics. A Biometrical approach 2 nd edition. McGram Hill Book Company Inc. New York 633pp. Vigna subtenuinea verde in Abakaliki Southeast Nigeria. I. Sc.Re.J. 2:6-20. Webster C.C and P.N Wilson 980. Agriculture in the Tropics. Longman Group Limited (2nd ed) pp