592Bulgarian Journal ong>ofong> Agricultural Science, 14 (No 6) 2008, 592-597Agricultural AcademyEFFECTS OF UREA-ENRICHED ORGANIC MANURES ON SOILFERTILITY, TEA SEEDLING GROWTH AND PRUNED YIELDNUTRIENT UPTAKE IN IBADAN, NIGERIAR. R. IPINMOROTI *1 , G. O. ADEOYE 2 and E. A. MAKINDE 31Japan International Research Center for Agricultural Sciences, Tsukuba, Ibaraki 305-8686, Japan2Agronomy Department, University ong>ofong> Ibadan, Ibadan, Nigeria 3. Lagos State University, Lagos,NigeriaAbstractIPINMOROTI, R. R., G. O. ADEOYE and E. A. MAKINDE, 2008. Effects ong>ofong> ong>ureaong>-ong>enrichedong> ong>organicong> ong>manuresong>on soil fertility, tea seedling growth and pruned yield nutrient uptake in Ibadan, Nigeria. Bulg. J. Agric.Sci., 14: 592-597Readily available farm wastes ong>ofong> plant and animal origins were ong>enrichedong> with ong>ureaong> at ratio 3:1 ong>ofong> nitrogen needong>ofong> tea plant (150 kg N ha -1 ) and NPK (25:5:5) were used to fertilize tea (Camellia sinensis L.) seedlings atIbadan, Nigeria. The ong>enrichedong> ong>manuresong> (cocoa husk, cow dung, poultry droppings, tea fluff and siam weed -Chromolaena odorata) resulted to higher soil fertility enhancement in N, P, K, Ca, Mg and ong>organicong> carbonbuildup than NPK and control (no fertilizer). Tea growth parameters and pruned dry matter yields were higherand similar for ong>enrichedong> ong>manuresong> and NPK but lower for control treatment plants. Nutrient contents ong>ofong> theong>enrichedong> manure treated tea plants were higher compared to those for NPK and control treated plants. About 3.0– 4.6, 0.08 – 0.21, 0.69 – 1.79, 0.36 – 0.76, 0.17 – 0.24 and 31.5 – 5.45 kg N, P, K, Ca, Mg and C ha -1 respectivelycould be recycled to the soil through pruned materials from tea seedlings treated with ong>enrichedong> ong>manuresong> comparedto 1.17, 0.05, 0.25, 0.69, 0.18 and 40.84 kg ha -1 for similar elements for NPK treated plants. About 67.3 %ong>ofong> the possible recycled nutrients are contained in the leaves. The C/N ratio ong>ofong> the pruned materials ranged from9.81 – 10.5. Poultry droppings and tea fluff were more efficient ong>manuresong> than others on the overall parametersand were hence recommended as alternative nutrient sources for tea plants.Key words: Enriched ong>manuresong>, nutrient uptake, soil fertility, tea seedlingsIntroductionE-mail: firstname.lastname@example.orgTea (Camellia sinensis L.) is a beverage cropcultivated for its fresh leaves (2 leaves + bud) in plantationsas monocrop and requires high soil nutrients,particularly N, P, K, Ca and Mg (Bore, 1996). Thesenutrients are critical and their deficiency and or inadequatesupply would eventually lead to poor tea seedlingestablishment and performance on the field. Teacannot therefore be produced optimally without fertilizerapplication. Soils ong>ofong> the tropics, Nigerian soilsinclusive, are inherently low in native fertility (Ogunwaleet al., 2002) and lack the capacity to support plantgrowth without external nutrient addition (Adeoye et
Effects ong>ofong> Urea-Enriched Organic Manures on Soil Fertility, Tea Seedling Growth....593al., 2005)Tea production is commercially by nutrient supplythrough inong>organicong> fertilizers at rates between 150 –300 kg N ha -1 for black tea (fermented tea) (Tsujiand Kinshita, 2001; Wanyoko et al., 1997) and up to1000 kg N ha -1 for green tea (unfermented tea)(Toyomasa, 2001). These rates are high and requireabout 50 % ong>ofong> the total annual farm variable inputs(Owuor, 1996). Presently there is a global short supplyand high procurement cost ong>ofong> inong>organicong> fertilizersand the poor resource farmers cannot afford this.There is need to lock for alternative nutrient sources,that are cheap, readily available and affordable to thefarmers. Heavy application ong>ofong> inong>organicong> fertilizers leadsto deterioration ong>ofong> soil cation exchange capacity(CEC) and clay contents ong>ofong> the soil, high concentrationong>ofong> Al and silicate in drainage water in addition toair pollution through nitrous gas emission, excessiveleaching leads to underground water pollution (Jarvis,1996; Prasad and Power, 1995). Most tropical soilsare low in ong>organicong> matter content and they need properong>organicong> matter management by way ong>ofong> ong>organicong> fertilizerapplication for sustainable long term land use. Thiswork was carried out to know the possibility ong>ofong> usingsome readily available ong>organicong> wastes, complementedwith inong>organicong> fertilizer for tea plant nutrition in Ibadansouthwestern Nigeria.Materials and MethodsFive ong>organicong> nutrients: cocoa husk, siam weed(Chromolaena odorata), tea fluff, cow dung andpoultry droppings were pulverized, analyzed andmixed with ong>ureaong> (45% N) at ratio 3:1 ong>ofong> N contents,while NPK (5:1:1) compounded by mixing ong>ureaong> (45%N) for N, Sokoto rock phosphate (33% P 2O 5) for Pand muriate ong>ofong> potash (60% K 2O) for K, were appliedto supply 150 kg N ha -1 for tea seedling nutritionat Ibadan, Nigeria. The tea seedlings were plantedin 10 kg soils in plastic pots and watered twice weeklyto 70 % field capacity and monitored for 12 months.Monthly data on growth parameters and growth componentswere taken. These includes: plant height fromsoil base to plant tip, girth at soil base with verniercaliper, number ong>ofong> leaves by visual counting and leafarea with leaf area meter. After 12 months, tea seedlingswere pruned at 30 cm height from the plant base,oven dried to constant weight at 65 0 C. Samples wereseparated into leaf and stem, weighed, milled and analyzedfor the N, P, K, Ca, Mg and ong>organicong> carboncontents. Soil samples were collected from the potsand processed in the laboratory for routine chemicalanalyses.Analytical proceduresSoilSoil samples collected before and after 12 monthscommencement ong>ofong> the experiment were analyzed fortheir N contents according to Kjeldahl, P by Bray 1method, while K, Ca and Mg were by leaching thesoils with 1M NH 4OAC and read out from atomicabsorption spectrophotometer (AAS) using the appropriatelamps. The ong>organicong> carbon (OC) contentwas according to IITA (1979).Manures and plant materialsThe ong>organicong> materials used as ong>manuresong> and thepruned tea plant parts were analyzed for their N contentaccording to Kjeldahl method. Total P, K, Caand Mg contents were read after ashing in a mufflefurnace at 500 0 C for 5 hours. The ash was dissolvedin 5 ml 4 % HCL, leached with distil water to 100 mllevel and P content determined by Molybdophosphoricacid blue colour method. The ong>organicong> carbon (OC)content was according to IITA (1979). Total K, Caand Mg were determined using an atomic absorptionspectrophotometer (AAS). The % N, P, K, Ca, Mgand ong>organicong> carbon contents were used to multiplythe weight ong>ofong> the dry matter to obtain the uptake. Thetotal nutrient contents were by addition ong>ofong> the resultantcomponent part values. Each value ong>ofong> the totalnutrient contents was multiplied by 16,667 to obtainthe expected nutrient content per ha for each nutrient.All values were subjected to analyses ong>ofong> variance andsignificant mean differences were separated using LSDat 5 %
594 R. R. Ipinmoroti, G. O. Adeoye and E. A. MakindeResults and DiscussionThe soil N (0.2 g/kg), available P (4.6 mg/kg) andong>organicong> C (4.2 g/kg) are considered low, while theexchangeable K (0.63 cmol/kg) and Mg (0.37 cmol/kg) values are moderate compared to the critical valuesong>ofong> 1.2 g/kg N, 6.0 mg/kg P and 30g/kg OC calculatedfor ideal soils for tea in Nigeria. The N and Pare critical nutrients for good tea nutrition. The lowlevel ong>ofong> these in the soil suggests that the soil need tobe supplemented with these nutrients for sustainabletea cropping on the soil. The ong>organicong> materials containsubstantial amount ong>ofong> N, P, K, Ca and Mg (Table1) with C/N ratio ong>ofong> 8 – 25 which are within the limitfor quick decomposition and nutrient release (Dogo,2001). The rate ong>ofong> nutrient release however, is expectedto be faster for poultry droppings, followedby tea fluff, cow dung, siam weed (Chromolaenaodorata) and least in cocoa husk.The plant height, girth, number ong>ofong> leaves and leafarea values showed that the tea plants responded favorablyto the applied fertilizers compared to control(Table 2). This was positively reflected in the higherpruned dry matter yield (PDMY) for the fertilizertreated tea plants than for control. However the ong>enrichedong>ong>organicong> fertilizer materials resulted to higherPDMY than NPK. The general superiority ong>ofong> the fertilizertreated tea plants over the control on the growthparameters and PDMY suggests the need for fertilizeraddition to the soil, while the usage ong>ofong> the ong>enrichedong>ong>organicong> fertilizers were better than NPK.Analytical results ong>ofong> the pruned materials showedthat fertilizer treatments gave significantly higher N, P,K, Ca and Mg uptakes over the control (Table 3).The ong>enrichedong> ong>organicong> fertilizers were generally superiorto the use ong>ofong> NPK on the uptake. The NPK andcontrol treated tea plants were high in ong>organicong> carboncontents. This coupled with the low macronutrientcontents, indicated that their PDMY contains mostlyroughage and was ong>ofong> lower quality compared to theong>enrichedong> ong>organicong> fertilizer treated plants. Quality ong>ofong>tea has been ascribed to be based on the level ong>ofong> N,P, K Ca and Mg contents, in addition to other chemicalproperties (Obanda et. al., 1996). The expectednutrient recycle to the field through the pruned materialsranged between 3.0 – 4.67 kg N, 0.08 – 0.2 kgP, 0.69 – 1.79 kg K, 0.36 – 0.76 kg Ca, 0.17 – 0.24kg Mg and 31.5 – 45.8 kg ong>organicong> carbon, comparedto 1.17 kg N, 0.05 kg P, 0.25 kg K, 0.69 kg Ca,0.18 kg Mg and 40.8 kg ong>organicong> carbon by NPK.The values were least in the control compared to NPK.This result was in trend with reports by Wanyoko andMwakha (1991). About 67.32 % ong>ofong> the nutrient uptakesin the pruned materials were contained in theleaf portion, with C/N ratio range ong>ofong> 9.81 – 10.5,showing that the materials could easily decomposeand become beneficial to the soil, especially in improvingP uptake (Dogo, 2001).The ong>ureaong>-ong>enrichedong> treatments were significantly(P
Effects ong>ofong> Urea-Enriched Organic Manures on Soil Fertility, Tea Seedling Growth....595Table 2Growth parameters and pruned dry matter yield (g/plant)TreatmentsHeight, cm Leaf area, cm 2 Pruned dryGirth, cm Leaves(Equivalent weight/ha)matter yieldCocoa husk (11.85 t/ha)+Urea (81.5 kg/ha)Cow dung (5.44t/ha)+Urea (81.5 kg/ha)Poultry droppings (3.75 t/ha)+Urea (81.5 kg/ha)Siam weed (4.5 t/ha)+Urea (81.5 kg/ha)Tea fluff (3.9 t/ha)+Urea (81.5 kg/ha)NPK (5:1:1)Urea (326 kg/ha)SRP (206.9 kg/ha)MOP (60.3 kg/ha)(150 N, 30 P & 30 K kg/ha)Control16.1332.523.1314.7525.8324.3817.333.853.863.553.754.54.333.218172710222117939.71005885.9395.9726.3966.9387.95.085.877.585.678.144.483.07LSD (5 %) 5.21 0.35 6.14 475.1 2.21SRP = Sokoto rock phosphate; MOP = Muriate ong>ofong> patash; LSD = Least significant figureTable 3Nutrient uptake (mg/plant) ong>ofong> pruned tea materialsTreatment N P K Ca Mg Organic CCocoa husk + Urea 250 7 23.4 19.8 8.8 2070Cow dung + Urea 230 6.8 13.2 22 12.1 2510Poultry droppings + Urea 340 12.8 54.5 37.3 18 3620Siam weed + Urea 220 7.5 32.3 26.7 13.5 2320Tea fluff + Urea 280 9.3 15.2 22.6 14.4 2880NPK 240 8 7 41.1 11 2460Control 220 5.3 5.9 9.3 2.3 2340LSD (5 %) 18.1 2.1 6.2 10.3 5.7 154.1LSD = Least significant difference
596 R. R. Ipinmoroti, G. O. Adeoye and E. A. MakindeTable 4Some soil nutrient contents after 12 months ong>ofong> tea cropping and treatment to enrichong>organicong> and NPK fertilizersTreatment N, g/kg P, mg/kgK Ca Mg Organic C,cmol/kgg/kgCocoa husk + ong>ureaong> 1.4 5.1 0.61 0.59 1.98 14.6Cow dung + ong>ureaong> 2.4 6.3 0.84 0.59 2.7 14.2Poultry droppings + ong>ureaong> 2.3 3.5 1.03 0.58 3.02 13.8Siam weed + ong>ureaong> 2.4 4.6 0.48 0.61 1.7 11.9Tea fluff + ong>ureaong> 2.3 3.4 0.55 0.61 2.08 13.1NPK 1.3 5.5 0.37 0.25 1.74 11.9Control 1 2 0.48 0.24 1.32 10.2LSD (5 %) 0.4 1.1 0.26 0.19 0.25 0.81LSD = Least significant differencelower values in nutrients and ong>organicong> carbon for thesoils under NPK and control indicated that tea productionwould not be sustainable without external ong>organicong>matter sources to probably modify the physical,chemical and biological conditions ong>ofong> the soil. This ismore so in that most Nigerian soils as in other tropicalregions, are fragile due to low ong>organicong> matter contents(Ayoola and Agboola, 2002).The Mg contents in the soils treated with NPKand control were twice lower in values compared tothe ong>enrichedong> manured soils. The difference might havebeen from the applications ong>ofong> the ong>organicong> ong>manuresong>which are rich in Mg contents (Table1). This showsthat with time, the soils treated with NPK and controlwould be in acute supply ong>ofong> Mg and its deficiencysymptoms would manifest. For sustainable managementong>ofong> the soil for optimal and good quality tea production,the use ong>ofong> ong>manuresong> in combination with ong>ureaong>as sources ong>ofong> balanced nutrient supply to tea plantswould be more appropriate. The use ong>ofong> inong>organicong> fertilizersas sole source ong>ofong> nutrient supply to tea plantson the field has been reported to lead to acute supplyong>ofong> Mg and the manifestation ong>ofong> its deficiency symptomson tea bushes at Kusuku in Mambilla plateauarea ong>ofong> Nigeria (Obatolu, 1999).ConclusionThe use ong>ofong> the ong>ureaong> –ong>enrichedong> ong>organicong> ong>manuresong>enhanced better tea growth, pruned dry matter yieldand nutrient uptake than the sole use ong>ofong> NPK (5:1:1)and helped to maintain the soil quality in terms ong>ofong> reservedsoil nutrient and ong>organicong> carbon contents. Thepoultry droppings and tea fluff were more outstandingcompared to other ong>manuresong> in this regard and weretherefore recommended for optimal nutrient supplyto tea plants as well as to help to maintain the soilquality for sustainable tea production over a long period.AcknowledgementsThe authors are grateful to the Executive Directorong>ofong> Cocoa Research Institute ong>ofong> Nigeria for the permissionto publish this research work.ReferencesAdeoye, G. O., M. K. C. Sridhar, O. O. Adeoluwaand N. A. Akinsoji, 2005. Evaluation ong>ofong> naturallydecomposed solid wastes from municipal dumpsitesfor their manorial value in southwest Nigeria. J.
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