Gmelina Arborea Roxb. (Yemane) at Tropical Plantation Forest

Growth Performance, Crop Productivity, and Water and Nutrient Flows in Gmelina arboreaRoxb. -Zea maysHedgerow Systemsin Southern Philippines

Rogaciano N. Miole I, Robert G. Visco 2, Damasa B. Magcale-Macandogv, Edwin R. Abucay3'4, Antonio F. Gascon2 and Arturo SA. Castillo2

'College of Forestry and Environmental Studies, Marawi State University, Marawi City, Lanao del Sur; 2lnstitute of Renewable Natural Resources, College of Forestry and Natural Resources, University of the Philippines Los Banos, College, Laguna; 3Ecoinformatics Laboratory, Institute of Biological Sciences, College of Arts and Science,Universityof thePhilippines Los Banos,College,Laguna; 'Department of Community and

Environmental Resource Planning , College of Human Ecology, University of the Philippines Los Banos, College, Laguna; *Corresponding Author, [email protected], [email protected]

Agroforestry is a dynamic and ecologically-based natural resource management system that integrates trees in the farm to diversify and sustain smallholder production for increased social, economic and environmental benefits. An important and beneficial feature of agroforestry system is the inflow of nutrients into the system, through leaf litterfall, stemflow and throughfall. This study determined the tree and crop growth performance, crop productivity, and water and nutrient flows in a Gmelina arborea - Zea mays hedgerow agroforestry system in Claveria, Misamis Oriental, Philippines. Experimental set- ups of G. arborea -Z. mays hedgerow systems with two spacing treatments (1m x 3m and 1m x 9m) were established in the study area. Standard sampling protocols were employed for the set of parameters monitored and measured in the study. Growth performance of trees along the hedgerows and maize crop in the alley areas was better in the wide spacing treatment (1m x 9m) than in the narrow spacing treatment (1m x 3m).Nutrient contents of maize biomass and Gmelina leaf litterfall were likewise higher when grown in wide spacing treatment. Higher amount of nitrogen (N) from leaf litterfall was observed in the same treatment. About 54% of the incoming rainfall landed in hedgerow systems as throughfall and only 1% as stemflow in both spacing treatments. Depths of stemflow and throughfall were slightly higher in the narrow spacing treatment. Water passing through stems and barks of trees showed higher K contents than throughfall. Throughfall however, exhibited higher ammonium (NH4f) and nitrate (NO3) contents. The results of this study showed that tree spacing greatly affected nutrient dynamics of hedgerow agroforestry systems. Inputs of nutrients into these hedgerow systems were via stemflow, throughfall, maize crop residues and leaf litterfall. The nutrient outflow of the two hedgerow spacing treatments was via crop harvest. In the wide spacing treatment, higher crop productivity per unit area contributed greater NPK losses compared with narrow spacing treatment.

Key words: Agroforestry system, litterfall, nutrient flows, stemflow, throughfall.

INTRODUCTION Combination of perennial crops (coffee, cacao, citrus and banana) and annual crops like cereals (corn, rice, Decline in agricultural productivity is a major problem sorghum), vegetables(mungbean, string bean, inthe Philippine upland areas. To address this, soybean or peanut), and other crops (sweet potato, SlopingAgriculturalLand Technology (SALT), a melon or pineapple) can be planted in the alley areas. simple conservation farming scheme, was introduced Varietyof crops growninthe hedgerow system initially in the Southern Philippines in the early 1980s. provides the farmer several harvests throughout the Sloping Agricultural Land Technology is a form of alley year and thus greater income. Fruits from trees may farming consisting of contoured rows of leguminous be tappedfor food and medicine.Duringfallow trees and shrubs where field and perennial crops are periods, the trees and shrubs in the hedgerows will plantedinalley areas in between the contoured grow and provide timber and charcoal after a few hedgerows. Height of the hedgerows was maintained years (Tacio 1991).SALT technology was widely at 1.5- 2.0 m and the leguminous cuttings were introducedthroughoutthecountrythroughthe applied as organic fertilizer in the alley areas (Tacio concerted efforts of the government (Department of 1991). Agriculture and the Department of Environment and NaturalResources)and manynon-government organizations. Hedgerow system is a form of agroforestry designed result from the incident precipitation falling through the forslopingareas.Agroforestryis adynamic, canopy ofthe vegetation, washout materials ecologicallybasednaturalresource management deposited as particles, gases or cloud droplets prior to system that integrates trees in the farm, to diversify the precipitation event, and exchange between the and sustainsmallholder productionforincreased canopy surfaces and the solution passing over them social, economic and environmental benefits (Leakey including nutrient leaching from and uptake by the 1996). Its main feature that distinguishes it from a canopy (Fan and Weitting 2001). Some nutrients such purely agricultural production system is the integration as calcium (Ca) and potassium (K) are added to the of treesinthe cropping system. Growing trees stem andthroughfall due to tree-atmosphere together with agricultural crops is perceived to provide interactions, whereas nitrate (NO3 -N) and ammonia a more effective plant cover to protect soil from (NH4÷-N ) nitrogen may be absorbed from rainfall by erosion, maintain soil organic matter, ameliorate soil the tree (Wang et al. 2000). productivity, augment N-fixation, and encourage a deeper or more prolific root system that enhances Over the past three decades, the scope and scale of nutrient cycling (Sanchez 1987), stimulates higher agroforestryresearcheshave widened,covering population of microorganisms, minimizes soil erosion, studies on tree-crop interaction, microclimate augments soilfertility, and sustains levels of crop regulation, water and soilconservation, and pest production (Kang 1997), and enhances biodiversity dynamics. However, very few studies on nutrient and microclimate changes (Garcia-Barrios and Ong inflows fromincidentprecipitation,stemflow and 2004). throughfall, decomposedlitterof trees and crop residues, and nutrient outflows from run-off and soil Pattanayak and Mercer (1998) valued soil erosion have been conducted. This study examined conservation benefits in contour hedgerows in Eastern and evaluated the nutrient flows in Gmelina arborea Visayas, Philippines using a bio-economic framework Roxb. - Zea mays agroforestry system in southern thatinvolved econometric analyses (weighted soil Philippines. quality index, regression and Cobb-Douglas profit function) of household data.Results of analysis of production data showed that market prices, education, MATERIALS AND METHODS farming experience, farm size, topography, and soil quality are positive covariates of household profits. Time and Place of Study Improving ormaintaining soil qualitythrough The study was conducted in Barangay Patrocenio, agroforestry investments can increase annual Claveria, Misamis Oriental in Mindanao, Philippines in production profits by 6% of total income.However, 2003 (Figure 1).Claveria is a land-locked agricultural these benefits are overridden by people's reluctance town in Misamis Oriental geographically located at 12° to practice alley cropping because of some problems 45' E longitude and8° 34'to8° 35' N latitude encountered. One is the significant reductionin (SAFODS 2003).Claveria has a generally rugged arable space for short-term agricultural crops because topography with gently rolling hills and more than 68% of the space occupied by contour hedgerows. Another of its total area having slopes over 18%. The soil is disadvantageisthat hedgerow vegetation,being Jasaan clay characterized as fine, mixed, woody perennials, takes long to fully develop to be isohyperthermic Ultic Haplorthox derived from effective in minimizing surface run-off and soil erosion. volcanic parent materials (Bureau of Soils 1985 as cited in SAFODS 2003). Claveria has 5-6 wet months An important and beneficial feature of agroforestry(>200 mm/month) and 2-3 dry months (<100 mm! system is the inflow of nutrients into the system. In an month). Rainfall patterns vary with elevation, with ecosystem where trees are dominant, the input of relatively higher rainfall in the upper areas than the elements to the soil is dominated by three pathways: lower portion (MPDC 1998 as cited in SAFODS 2003). litterfall,throughfall,and stemflow (Peterson and The experimental plots had an elevation of 542-554 Hansen 1999). Among thethree, litterfall is masl, slope of 3.18-4.13% and an aspect of 190° considered the major pathway of nutrients (Haase facing south. 1999), which are released by decomposition and leaching or mineralization (Regina 2000). On the Experimental Treatments and Design otherhand, throughfall and stemflownutrient Gmelina arborea and Zea mays hedgerows were compositions are governed by a complex interaction planted in 1 m x 3 m hedgerow spacing as treatment 1 of atmospheric, hydrologic and biochemical processes (narrow spacing) and 1 m x 9 m hedgerow spacing as (Moreno et al. 2001). Precipitation washes minerals treatment 2(widespacing). Eachplot had a from the atmosphere, and are deposited on thedimension of 18 m upslope and 10 m across the leaves. From the leaves, water carries the dissolved slope.There were 3 strips in1 m x 9 m spacing minerals into the soil where they are absorbed by the treatment and 9 strips in the 1m x 3 m spacing roots,transportedinthe stream, orlost through treatment. A buffer zone of 6 m between treatments leaching and erosion (Waring and Running 1999). The was established.The study was laid out in RCBD chemicals in throughfall and stemflow are supposed to with two replications.

RN Miole et al 35 Philippine Sea 9 2 4 12 se, 114sonselers

4* " ti South China Sea

I- r

Legend j Muni o Boundary 11111 Made,gulnci Concerned Barangays Mil P °Hat:ion

aibacunipri I Rizal Celebes I= Gumad Sta. Cruz Sea soHi roplanan Figure 1. Location and map of the municipality of Claveria, Misamis Oriental.

Maize Planting and Field Maintenance Tree Height and Diameter at Breast Height (DBH) Land preparation activities were done at the onset of The height and diameter at breast height (DBH) of 10 the rainy season. The alleys were cleared of weeds a randomly selected Gmelina trees in each treatment week prior to plowing with a carabao-drawn-single plot were measured using clinometer and diameter blade moldboard at a distance of 60 cm between tape,respectively.Periodic measurements of tree furrows. Seeds of high-yielding maize variety (Pioneer height and DBH were done at 3-mo interval during the 3014) were planted in the alley area at a planting study period. distance of 25-30 cm between hills. One to two seeds of maize were sown per hill using the dibble method of Maize Sampling and Analyses planting. Nitrogenfertilizer(Urea46-0-0) and Sixteen sample plants were harvested from the middle Phosphorus (P205) fertilizer (Solophos 0-18-0) were portion of the plot (within the middle 10 m). The applied based on the fertilizer recommendation rate harvested maize plants were segregated into stems, for the site (Table 1).Other management practices leaves, tassels and ear, and fresh weight of each and schedules are shown in Table 1. plant part was determined. A 1-kg fresh sample of each segregated maize plant parts was taken for oven Data Collection drying at 70°C for 48 h to determine its moisture Soil Profile Characterization content (MC) and dry matter (DM) content. The standard procedure for soilprofile description established by the Soil Conservation Service, United Yamoah and Burleigh's (1992) formula was used to StatesDepartmentofAgriculture(USDA) was compute the grain yield of maize per unit area: adopted to characterize the soilin the study area (SSDS 1993). Y = 1_5.x Ya x1000 W VV x L Soil Sampling and Analyses Ten random auger borings were dugg within each where: Y = yield (kg ha-1) experimentalplot. A 1-kg composite sample was S = alley crop spacing collected from each treatment plot for soil analysis. L = length of subplot The soil pH, total N, available P and exchangeable K Ya = unadjusted yield (kg per subplot) were analyzed using Potentiometric, Kjehldahl, P-Bray W = alley width (m) and Flamephotometer methods, respectively. Total N, P and K contents of the maize biomass were analyzed using Micro Kjehldahl, Vanadomolybdate and Flame Photometer methods, respectively.

36 Growth, productivity, water and nutrient flows in hedgerow systems Table1.Schedule of activities and management practices used in the field experiment, Brgy. Patrocenio, Claveria, Misamis Oriental. Activities/Management Schedule Practices 1. First cropping season Feb.-May Second cropping season Jul.-Oct. 2. Fertilizer application Urea (46-0-0) at 195.65 kg ha-1 30 DAE Solophos (0-18-0) 66.67 kg ha-1 at planting 3. Interrow cultivation 30 & 60 DAP 4. Weeding 30 & 60 DAP 5. Harvesting 110-120 DAP

Ottertail Production Four litter traps were randomly installed inside each Figure 2. Location of the litter traps, stemflow and hedgerow plot (Figure 2).Eachlittertrap had a throughfall set-up under the 7-year old G. dimension of 1 m x 1 m and raised 1 m above the arborea hedgerow intercropping system. ground. Litterfall was collected from the litter traps every month. The collected litterfall was segregated into different fractions, namely: leaves, flowers, bark, t01110 0 0 is mm twigs and fruits. Each fraction was weighed separately and a sample fraction brought to the laboratory for mm oven-dry weight determination. The litter sample was oven-dried at 70°C for 4 days until a constant weight o sic4 0 mm was obtained. mm mm mm - Hedgerovv trees Analysis for nutrients of the leaflitter was done mm - Throughfall collectors followingMicroKjehldahl,Vanadomolybdate and mm A - Sternflow setup Flame Photometer methods for N. P and K contents, respectively. 00well000 0 0 Precipitation Measurements Rain gauge (Tru-Chek0) was installed in an open 0 0000 0 0 area within the experimental site to record the incident precipitation. The depth of rainfall was recorded every 0000 6 mo rain event. For stemflow (SF) collection, four stemflow 0000000 collectors were installedin four randomly selected treesineach experimentalplot(Figure3).The 00000Cr 6 collection method was based on the works of Cape et o !! al. (1991) as cited and used by Gascon (1994). Plastic 0o 0 hose of 2.54 cm diameter was slit and coiled around 0o" a 0' the stem of the tree at breast height (1.3 m) (Figure m 4). A 63.5-cm x 127-cm cellophane bag was placed at 0 o o o o o the lower end of theplastic hose tocollect the m stemflow. The depth of collected stemflow was osso0" calculated as follows: 0n m 0 0 0111 The canopy area of the tree was estimated based on Figure 3. Schematic layout of the location of stemflow area of a circle. Canopy radius of the four randomly and throughfall set-up under 7-year old G, selected trees was measured and averaged following arborea hedgerow intercropping system: (a) the cardinal directions. 1x3 m and (b) 1x9 m hedgerow spacing. SF _ Volume of SF(cm3)= cm depth x 10 = mm depth Canopy area (cm (mm) (Gascon 1994). Depth of TF was computed Throughfall (TF) was measured using 1-gal (3.78 L) as follows: containers randomly installed at each drip zone and at Volume of TF (cm3 the midway zone of the treatment plots. A total of 16 TF - ) - cm depth x 10 = mm depth TF collectors were installed in each plot. The volume Surface area of (mL) of throughfall at each rain event was measured collecting container (cm2) using a graduated cylinder and converted to depth

RN Miole et al 37 Table 2. Soil Physico-chemical properties of the layers of a soil profile in the experimental area, Brgy. Patrocenio, Claveria, Misamis Oriental.

Soil 0/0 K (cmol depth (+) kg-1 pH Texture OM VA)) (cm) (ppm) soil) 0-28 3.460.179.19 0.17 4.6 light clay

28-42 2.430.129.30 0.13 4.7 heavy clay 42-57 1.720.094.64 0.13 4.8 heavy clay 57-85 1.200.064.64 0.09 4.7 heavy clay 85-127 0.71 0.044.66 0.06 4.8heavy Figure 4.Stemflow (sack-sized plastic bag) and clay throughfall collector (1-gallon container) 127 0.500.029.36 0.08 5.0 heavy used in the study. clay

Water samples from incident precipitation, throughfall Tree Growth and Performance and stemflow were analyzed for N (NO3), P and K Trees grown in wide spacing treatment (wide spacing) using Phenol disulfuric acid. Flame photometer and had bigger DBH than trees grown in narrow spacing Modified Molybdovanado Calometric methods, treatment (narrow spacing) (Figure 5).This means respectively. that growing conditions for trees is much better in wide spacing because of the availability of light and nutrients from the soil. Competition for light and soil Statistical Analyses nutrients among trees in the hedgerows was much The data gathered were analyzed using SYSTAT. lessinwidespacingthan innarrowspacing. Treatments with significant differences were further Bertomeu (2003) found thatG. arboreahedgerows at analyzed by Scheffe test. 1 m x 10 m spacing attained a height and DBH of about 17 m and 20 cm, respectively, after 4 years. Maize Grain Yield and Biomass RESULTS AND DISCUSSION Maize grain yield and biomass were higher in wide Soil Profile Physico-chemical Characteristics hedgerow spacing (wide spacing) thaninnarrow hedgerow spacing (narrow spacing) for both cropping The soil profile of the experimental area has a depth seasons (Table 3).The difference in grain yield and of about 127 cm. The uppermost layer (0-28 cm) has high organic matter (OM, 3.46%) and N (0.17%) biomass between the two spacing treatments was relativelysmallduringthedrycropping season contents. The OM and N contentsof thesoil decreased with depth (Table 2). The soil has low P (February-May),butsignificantduringtherainy cropping season. The same trend was also observed (4.6-9.3ppm) and K (0.06-0.17 cmol kg-1 soil) contents. Both P and K contents decreased with on an annual-basis (Table 3). increase in depth except, wherein higher levels of both P and K were observed at the deepest layer (127 The annual maize grain yield in wide spacing (1,340 mm) (Table 2). The soil is acidic, with pH ranging 4.6 - kg ha-1) was slightly higher than in narrow spacing 5.0.Soil texture is light clay at the topmost horizon (1,163 kg ha-1).While Bertomeu's (2003) study in and heavy clayinthe lower horizons. Soilsin Claveria achieved a total maize grain yield of 3,500 kg Claveria have a depth of more than 1 m (Garrity and ha-1 for two croppings (wet and dry) under 1 m x 10 m Agustin 1995), and are characterized by high organic 4-year-oldG. arboreahedgerow, this was almost matter content, low pH (4.2-5.2), low cation exchange thrice higher than the maize grain yield obtained in capacity (CEC) and low anion activity (Hafner 1996; this study.The later part of the growing season of CLUP 2000). maize during the second cropping in this study was also affected by the El Nino phenomenon, resulting in Degraded upland areas are generally characterized climatic variations in terms of rainfall that significantly by acidic soils, low P contents and low CEC values. A reduced crop growth compared with the first cropping. number of developmentprojectsbased onthe Competitionforlight,nutrientsandwaterare promotionofsoilconservation technologies have important factors affecting crop growth and yield in a been implemented including sloping agricultural land hedgerow agroforestry system. Wider spacing of the technology (SALT) (Cramb 2000), community-based hedgerows allows greater light for the maize crop, forest management (CBFM), reforestation and while in the narrow-spaced hedgerow, shading of the establishment of agroforestry systems (Laietal. crop can be a major problem. 2000).

38 Growth, productivity, water and nutrient flows in hedgerow systems 300 - 16 2050

14 20.00

12 1950 - +- 1m x 3m 19.00 - IF- 1m x 9m 8 .% 1850

18.00

17.50

17.00 2 15.00 17.00 19.00 21.00 23.00 A DBH (cm) Month Figure 5. Mean DBH and height of G. arborea Roxb. Figure 6. Monthly rainfall pattern and number of rainy hedgerow agroforestry system with daysin theexperimentalarea, Brgy. different spacings. Patrocenio,Claveria, MisamisOriental, Philippines.

Table 3. Maize yield and biomass under G. arborea

hedgerowRoxb. agroforestry system, 7.00 - 300 lm ic3m Claveria, Misamis Orientall. 6.00 - - -* -rainfall Yield Biomass 250 (kg ha-1) Cropping (kg hal 5.00 - Season lm x x lm x x 200 3m 9m 3m 9m First (Feb.-May) 922a 958a 3,051a 3.155e 150L". 471 Second (Aug.-Nov.) 241a 382a 1,631a 4,813ab

Total (kg ha-1 yr-1) 1,163a1,340a 4,682a 7,968ab 100 'Means in a row under the same parameter followed by the same letter are not significantly different at p=0.05 1.00 - 50 a a aa ;41' a a axi Water Dynamics in Agroforestry Systems 0.00mi,111111 Precipitation A A 0 There were 95 rainfall events recorded within the Month study period from February to October 2004 with a Figure 7. Depth of stemflow under G. arborea Roxb. total depth of 1,474.73 mm (Figure 6). June had the hedgerow agroforestry systems,Claveria, highestrainfall(256.57mm),followedby August MisamisOriental, Philippines. Different (234.70mm), whereas April had the lowest lettersindicatesignificantdifferences by (36.32mm). However, no pronounced dry and wet Scheffe test between hedgerow treatments periods were observed at the time of the study. at each sampling month (P 5 0.05). Typically, Claveria has an average rainfall of 2500 mm in wet season from June to December and short dry narrow spacing during the months of July, August and season from March to April. At the time of the study, October.Higheststemflowmeasurementswere there was plenty of rainfall even during the dry months observed in August with depths of 5.96 mm (narrow of March and February (Figure 6). spacing) and 4.31 mm (wide spacing) (Figure 3). Lowest stemflow measurements were recorded in Stemflow April with only 0.09 and 0.05 mm for narrow spacing Mean DBH oftrees sampledfor stemflow and wide spacing, respectively (Figure 7).Generally, measurements for 1 m x3 m (narrow spacing) and 1 higher stemflow measurements were obtained during m x 9 m (wide spacing) hedgerow spacing treatments the months of high rainfall events and low stemflow were 23.49 and 23.50 cm, respectively. On the other measurements were obtained during the dry months. hand, tree height was 20.29 and 20.14 m for narrow Therelativelyhigher stemflow measurementsin spacing and wide spacing, respectively. The stemflow narrow spacing could be attributed to the higher measurements in this study showed no significantdensity of trees in this treatment (60 trees/180 m2) difference between the two spacing treatments in all compared with wide spacing (20 trees/180 m2). The sampling months (Figure 7). However, the total depth stemflow measurements (0.05 to 5.96) in this study of annual stemflow was relatively higher in narrow paralleled the findings of other researchers spacing (16.47 mm) than in wide spacing (15.36 mm). (Shachnovich et al. 2008; Johnson 1990). Higher stemflow measurements were recordedin

RN Miole et al 39 Throughfall 1 in z 3m 300 I I lm x9rn The total depths of throughfall monitored during the 9- 180 rainfall month study period were 797.50 and 764.14 mm for 250 160 narrow spacing and wide spacing, respectively (Figure 140 8),although these values were notsignificantly 200 20 - different. Highest throughfall values were recorded in E E S August. It was also noted that throughfall varied 100 150i temporally between the two spacingtreatments. 110 100 During May and June, throughfall was relatively higher 60 in narrow spacing while during February, March, July 50 and September,throughfall was higherinwide 20 spacing. Throughfall was significantlyhigherin 0 narrow spacing than in wide spacing in June (Figure A s 0 8).This could be attributed to the smaller canopy of trees grown at closer spacing. Figure 8. Depth of throughfall under G. arborea Roxb. hedgerow agroforestry systems,Claveria, Results of thisstudy complement theresults of MisamisOriental, Philippines. Different several other studiesthat have shown that the lettersindicatesignificantdifferencesby quantity of stemflow and throughfall is influenced by Scheffe test between hedgerow treatments tree density, interregional differences in precipitation at each sampling month (P 5_ 0.05). volume,intensity,seasonaldistribution,and gap fraction (Shachnnovich et al. 2008; Park and Cameron Table 4. Total litterfall, leaf litter nutrient analysis and its 2008; Balieiro et al. 2007; Xu et al. 2005; Levia and estimated nutrient content under 7-year old G. Frost 2003; Mahn et al. 2000). arborea hedgerow agroforestry system. Leaf litter Estimated Total nutrient nutrient content Summary of Water Flows in Hedgerow Systems Treatment litterfall analysis (%) (kg ha-1) About 54% ofincomingrainfalllandedinthe (kg ha-') hedgerow systems as throughfall, while only 1 % of N P K N P K the incoming rainfall landed as stemflow (Table 4). T1 (1m x 3m) 7,187 1.47 0.10 0.15 105.65 7.1910.78 The relatively higher total depth of stemflow and T2 (1m x 9m) 9,051 1.47 0.07 0.13 133.05 6.3411.77 throughfall in narrow spacing than in wide spacing

(Table 4) could be attributed to the higher density of 1400 - trees in the former resulting in greater tree canopy lm x3rn lm x9rn

1200 8111 and tree stems through which rainfall passed through. a The rain water that passed though the canopy of trees in wide spacing was captured more as throughfall 1000 1 a instead of stemflow due to the general horizontal .c I. co 800 IN IN orientation of the G. arborea branches.In narrow IN 1111 IN : spacing,however,branches of trees wereina .Fg, 600 IN * . IN generally upward inclined orientation, thus rain water IIN IN was captured more as stemflow than throughfall. IN IN IN 200 - IN Nutrient Dynamics IN 111 Litterfall Production and Nutrient Content IN 1ii The monthly litter production of the 7-year-old G. M A MJ A S 0 N D arborea hedgerow agroforestry system is shown in Month Figure 9.Generally, higher litterfall was observed Figure 9. Litterfall under G. arborea Roxb. hedgerow during the dry season (January-May) in both spacing agroforestry system, Claveria,Misamis treatments (Figure 9). In the 11-month period, total Oriental. Different letters indicate significant litterfallinwidespacing(9,051 kg ha') was differences by Scheffe test between significantly higher than in narrow spacing (7,187 kg hedgerow treatmentsateachsampling hal). month (P0.05). Litterfall production peaked during the dry season environment factor by itself controls the timing of leaf occurrence, enabling the because of low rainfall fall in tropical forests, bearing in mind the many tree Gmelinato shed itsleavesas homeostatic species in a wide range of forest_ s with highly variable lossofmoisture mechanismagainstexcessive micro-environments. Gascon's (1994) study on leaf through transpiration-induced factors in litter fall, such litter production approximated that Gmelina + cacao as: wind speed, incident radiation and relative air and Gmelina + coffee stands had a litterfall of 7,976 humidity (Halenda 1989; Gascon 1994). No single and 9,668 kg ha' respectively. Further, Adu-

40 Growth, productivity, water and nutrient flows in hedgerow systems Anning et al. (2005) found that the annual total litter of Table 5. Nutrient analysis of selected water pathways a 12 m x 12 m G. arborea was between 1.2 - 8.1 t ha-1 under 7-year old G. arborea hedgerow agro- with 60% of the total litterfall occurring during the dry forestry system. season. Available N Treatment Parameter (ppm) 1K (ppm) In this study, the total amount of litterfall in narrow NH4+ NO3IPPin' spacing (7,187 kg ha1) is less than in wide spacing T1 (1m x 3m)Stemflow 4.56 5.26 7.00 38.00 (9,051 kg ha-1) (Table 4).Results of nutrient analysis T2 (1m x 9m)Stemflow 5.12 6.2413.0028.00 ofGmelinaleaflitterfallshowedthatthe N T1 (1m x 3m)Throughfall 5.70 8.00 4.80 4.20 concentration of Gmelina leaves was similar in both T2 (1m x 9m)Throughfall 4.20 6.60 2.10 9.20 2.57 4.12 2.00 trace spacing treatments (1.47%). Since litterfall was higher Rainfall in wide spacing, it follows that the amount of N that elements caught by the canopy. Moreover, large would come from the decomposition of Gmelina leaf amounts of elements are collected through contact litter would be higher in wide spacing. The P and K with stembark and moss. contents of leaf litter from narrow spacing were higher than that from wide spacing. However, the quantity of Liu et al. (2002) revealed that enhancement in nutrient litterfall in wide spacing was greater than in narrow concentration particularly N as well as P with respect spacing. The estimatedamountsofnutrients to rainfall is 2-5 times, while K is much higher and contained in the litterfall were 105 and 133 kg ha-1, 7.2 more variable (10-48 times). Dezzeo and ChacOn and 6.3 kg P ha', and 10.8 and 11.8 kg K ha-1 for (2006) found that mean annual K nutrient enrichment narrow spacing and wide spacing, respectively (Table of throughfall in tropical forest ranges 18-24 times. 4). The resultsof thisstudy revealedthatnutrient concentration of stemflow + throughfallin narrow The total annual NPK contents of litterfall in this study spacing with respect to rainfall was enhanced by as were within the range as reported by Adu-Anning et much as 2, 2, 3 and 38 times for NH4+-N, NO3 -N, P al. (2005) with 106 kg ha-1 of N, 11 kg ha' of P and and K, respectively. On the other hand, NH4+-N, NO3 - 117 kg ha' of K contained in the litterfall of a 12 m x N, P and K nutrient enhancement in wide spacing with 12 m G. arborea in Ghana. Agus' (2001) study respect torainfall was 2,1.5, 6 and 28 times, showed that total annual litterfall of a 6-year old G. correspondingly (Table 5). arborea Roxb. plantation in Indonesia was 7.6 t ha' with N, P and K contents of 86, 7 and 35 kg ha-1, Nutrient content of Maize Grain Yield and Biomass respectively. The nutrient contents (N, P, and K), yield and biomass of maize crop were relatively higher in wide spacing NPK from Stemflow and Throughfall than in narrow spacing (Table 6). Heckman et al. NR4+-N, NO3 -N, P and K contents of stemflow and (2003) reported in their study that maize grain can throughfall were analyzed for a single rain event and remove 11.0, 3.34 and 4.06 g kg-1 of N, P and K, results are shown in Table 5.The NH4+-N, NO3 -N, respectively. In this study, NPK removal in narrow and P concentrations in stemflow and run-off were spacing was 6.6, 0.31 and 5.86 kg ha', and 11.11, higher in wide spacing (Table 5) than in narrow 0.99 and 13.29 kg ha' for wide spacing. On the other spacing. On the other hand, NI-14.-N, NO3 -N, and P hand, P was considered the least nutrient removed by contents of throughfall were higher in narrow spacing harvesting. Phosphorus deficiencyinsoils due to than in wide spacing, except for K. K contents of fixation by the acidic soil, could have contributed to stemflow was higher in narrow spacing while the K the unavailability of P to plants and less vulnerable to contents of throughfall and run-off were higher in wide loss and gain. spacing (Table 5). Higher concentrations of N and K in maize biomass HOIscher et al. (2003) studied the internal partitioning were obtained compared with P (Table 6).Between of nutrient fluxes in stemflow and throughfall in three spacing treatments, N, P and K concentrations of the successional stages of upper montane rain forest in maize biomass were higher in wide spacing than in Costa Rica. They concluded that the small canopies narrow spacing (Table 6). N is considered more and inclined branches of trees contribute to the high mobile than P and its availability changes seasonally nutrient fluxes in stemflow in secondary forest stands. and rapidly in response to biological activities, while some of its forms are readily leached. Hanway (1962) The present study showed that stemfiow had much reportedthatas maizegrainformationbegins, higher P and K contents than throughfall. NH4+-N and translocation of N from all other plant parts to the NO3 -N contentsofthroughfallhowever,were grain occurs.At maturity, the maize grain contains relatively higher in throughfall than in stemfiow (Table about 62-70% of the total N in the maize plant. In 5).Several studies also documented the same trend contrast with other plant nutrients, K is largely stored for nutrient fluxes in throughfall (Balieiro et al. 2007; in plant biomass. Itis taken up by plants in large Dezzeo and Chacon 2006; Xu et al. 2005; Holscher et quantities during their vegetative growing period as al. 2003). Liu et al. (2002) reported that water flowing compared with all other elements except N (Tisdale along the tree branch and tree trunk surface contain and Nelson 1976; Hanway 1962).

RN Miole et al 41 Table 6. Nutrient content of the maize grain yield and biomass under a arborea Roxb.hedgerow agroforestry system, Claveria, Misamis Oriental. Nutrient Content Yield' Biomass' Nutrient (°/o) (kg ha-' yr") (kg ha-' yr") 1m x 3m 1m x 9m lm x 3m lm x 9m lm x 3m 1m x 9m N 0.40 0.56 4.65a 7.50a 18.73a 44.62a P 0.02 0.05 0.23a 0.67a 0.94a 3.98ab K 0.38 0.67 4.42a 8.98a 17.79a 53.39ab 'Means in a row under the same parameter followed by the same letter are not significantly different at p=0.05

Summary of Water and Nutrient Flows inG. Narrow Spacing Wide Spacing arborea Hedgerow System i--- Inthis study, selected processes were chosen to ' ;-kr-Als:kr represent the major nutrient flows in a 7-year-old G. arborea hedgerow intercropping system. Stemflow, I iree Lr:erfai throughfall, crop biomass residues and litterfall were I classified as processes contributing to nutrient inflows, CropRESsf-tES while crop harvest represented processes for nutrient , I outflows (Figure 10). Tree leaf litterfall was the major sourceof Ninputin bothhedgerow spacing 11-oi.rrl-Han treatments (Table 7) On the other hand, maize crop IF i residue was another source of N input for wide 5.-_criIcr.c spacing (Table 7).In wide spacing, N was lost mainly ir I via crop harvest . ICrop larcs-,

I t The tree leaf litter contributes higher nutrient input I particularly N that can be returned to a hedgerowFigure 10.Comparative nutrient flows in the narrow agroforestry system. The hedgerow trees can also and wide spacing hedgerow systems. contribute N via deep nutrient capture. This may become part of nutrient input being transferred to the Table 7. Nutrient analysis of Z. mays biomass and G. soilviatreelitterdecomposition. The hydrologic processes such as stemflow and throughfall can also Nutrient (%) nutrientsina Treatment Parameter contributesignificant amounts of N P K hedgerow agroforestry system. Nutrient content of T1 (1m x 3m)Maize biomass 0.40 0.02 0.38 crop biomass in the alleys depends on the amount of T2 (1m x 9m) Maize biomass 0.56 0.05 0.67 biomass produced under different hedgerow spacing T1 (1m x 3m) Litterfall 1.47 0.10 0.15 regimes. T2 (1m x 9m) Litterfall 1.47 0.07 0.13

CONCLUSION Inputs of nutrients into these hedgerow systems are via stemflow, throughfall, maize crop residues and leaf The growth performance of trees along the hedgerows litterfall.The nutrient outflows of the two hedgerow and maize crop in the alley areas is better in the wide spacing treatments are via crop harvest. In wide spacing treatment (wide spacing) than in the narrow spacing treatment, crop harvest contributed to greater spacing treatment (narrow spacing). Nutrient contents losses of NPK nutrients as compared with narrow of maize biomass and Gmelina leaf litterfall are higher spacing. in widespacingtreatment.Widerspacingfor hedgerow trees. is conducive for the intercropped The results of the present study have shown that tree maize to grow well, resulting to higher biomass and spacing affects the nutrient and water dynamics of yield and corresponding NPK nutrient uptakes. Higher hedgerow agroforestry systems. Wide hedgerow amount of N from leaf litterfall was observed in wider spacing had higher nutrient inflows and outflows while spacing treatment. narrow hedgerow spacing had higher depths of stemfow and throughfall. About 54% of theincomingrainfallentersthe hedgerow systems as throughfall and only 1% as stemflow in both narrow and wide hedgerow spacings. RECOMMENDATIONS The depths of stemflow and throughfall are slightly higher in the narrow spacing. Water passing through Based on the results of nutrient dynamics of this stems and barks of trees has relatively higher K study, wider hedgerow spacing is recommended to contentthanthroughfall. Ontheotherhand, farmers practicing Gmelina arborea-Zea mays throughfall, had higher NH4+ and NO3- contents. hedgerow systems. Long-term finetuning of

42 Growth, productivity, water and nutrient flows in hedgerow systems methodologiesoffieldexperimentswithgreater [CLUP] Comprehensive Land Use Plan. 2000. Claveria number of replicates should be done tomonitor MunicipalDevelopment Council,Claveria,Misamis nutrient dynamicsinthese agroforestry systems. Oriental, Philippines. 277 p. Additional measurements of stemflow and throughfall Cramb RA. 2000.SoilConservation Technologiesfor and its nutrient contents throughout the rainy season Smallholder Farming Systems in the Philippines: A should be conducted.Moreover, measurements of Socioeconomic Evaluation. Canberra: Australian Centre nutrient leaching, soil erosion and water run-off should for International Agricultural Research. ACIAR also be added to quantify nutrient losses via these Monograph No. 78. 228 p. processes.This study should also be replicated in Dezzeo N, ChacOn N. 2006. Nutrient fluxes in incident other sites to compare spatial differences of nutrient rainfall, throughfall, and stemflow in adjacent primary balancesandtovalidatethepresentfindings. and secondary forests of the Gran Sabana, Southern Different agroforestry configurations can be explored Venezuela. Forest Ecol Manag 234: 218-226. to address the need to increase farmers' income and household food security (e.g., optimum wide spacing, Fan HF, Weitting H. 2001.Estimation of dry and canopy exchange in Chinese fir Plantation. Forest Ecol Manag use of fruit-bearing trees). 147: 99-107. Garcia-Barrios L, Ong CK. 2004. Ecological interactions, AKNOWLEDGMENT management lessons and design toolsintropical agroforestry systems. Agroforest Sys: 61: 221-236. This paper was part of the PhD dissertation of the Garrity DP, Agustin PC. 1995. Historical land use evolution major author(Dr. Rogaciano N. Miole)atthe ina tropical acid upland ecosystem. Agr Ecosyst University of the Philippines Los Baf los. This study Environ 53: 83-95. was part of the Workpackage 3 of the Smallholder Gascon AF. 1994.Nutrient return and some hydrologic Agroforestry Options for Degraded Soils (SAFODS) characteristics of Coffee robusta L (Pub) and Grnelina Project funded by European Union (Contract No. ICAO arborea Roxb. and Theobroma cacao L and Gmelina -CT-2001-10092). The authors would like to thank the arborea Roxb. agroforestry systems in Mt. Maki ling. collaboration of farmers and local government of Brgy. [PhD Dissertation] College, Laguna,Philippines: Patrocenio, Claveria, Misamis Oriental. University of the Philippines Los Banos. (Available at UPLB Library). Haase R. 1999.Litterfall and nutrient return in seasonally REFERENCES flooded and fon-flooded forest of antanal, Mato Grosco, Brazil. Forest Ecol Manag 117: 129-147. Adu-Anning C, Safo EY, Abeney EA. 2005. Litter-fall and nutrientreturrninGmelina arboreashortrotation Hafner JAH. 1996. Soil Conservation Adoption within the woodlot: Implications for siteproductivity. Ghana J PovertyRachet:A CaseofContour Hedgerow Forest 17: 44-55. Intercroppingin the Upland Philippines. [Master of ScienceThesis].UniversityofCalifornia, Davis, AgusC.2001.Netprimaryproductionandnutrient California, USA. absorption of fast growing Gmelina arborea Roxb. (yemane) at tropical plantation forest. Indonesian J Agri Halenda C. 1989. Biomass estimation of Acacia mangium Sci 1: 46-52. plantations using allometric regression. Nitrogen Fixing Tree Research Reports 7: 49-51 Balieiro FC, Franco AA, Fontes RLF, Dias LE Campello EFC, de Faria SM. 2007. Evaluation of the throughfall Hanway JJ. 1962. Corn growth and composition in relation and stemflow nutrient contentsin mixed and pure to soil fertility:II. Uptake of N, P, and K and their plantationsofAcaciamangium,Pseudosamenea distribution in different plant parts during the growing guachapele and Eucalyptus grandis. Rev. Arvore 31(2): season. Agron J 54: 217-222. 339-346. Heckman JR, Simsb JT, Beeglec DB, Coaled FJ, Herberte Bertomeu MG. 2003. Smallholder maize-timber agroforestry SJ, Bruulsemaf TW, Bamka WJ. 2003. Nutrient removal systems in Northern Mindanao, Philippines: Profitability by corn grain harvest. Agron J 95: 587-591. and contribution to the timber tndustry sector, International Conference on Rural Livelihoods, Forests Holscher D, Kohler L, Leuschner C, Kappelle M. 2003. and Biodiversity, Bonn. 19-23 May 2003, available at Nutrient fluxesin stemflow and throughfall in three http: / /www.cifor.cgiar.org/ publications/corporate/ successional stages of an upper montane rain forest in cdroms/bonnproc/pdfs/ papers/ Costa Rica. J Trop Ecol 19: 557-565. T3_FINAL_Bertomeu.pdf, viewed 22 May 2007. 25 p. Johnson RC.1990. Theinterception,throughfalland Bureau of Soils. 1985. Detailed reconnaissance soil survey stemflow in a forestinhighland Scotland and the suitabilityclassification; Claveriacomplementation comparison with other upland forests in the U.K. J of project, Claveria, Misamis Oriental. Bureau of Soils, Hydro! 118: 281-287. Manila, Philippines. Kang BT. 1997. Alley cropping - soilproductivity and Cape JN,Brown AHF, Robertson SMC, Howson G, nutrient cycling. Forest Ecol Manag 91: 75-82. Paterson IS. 1991. Interspeciescomparison of throughfall and stemflow at three sitesin Northern Lai CK, Catacutan D, Mercado Jr AR. 2000. Decentralizing natural resource management: Emerging lessons from Britain. Forest Ecol Manag 46: 165-177. ICRAF collaboration in Southeast Asia. In: Enters T,

RN Miole et al 43 DurstPB,VictorM,editors.Decentralization and Regina IS. 2000. Biomass estimation and nutrient loss in Devolution of Forest Management in Asia and the four Quercus pyrenaica in Sierra de Gata Mountains, Pacific. Bangkok, Thailand: RECOFTC Report No. 18 Salamanca, Spain. Forest Ecol Manag 132(2-3): 127-141. and RAP Publication 2000/1. Riha SJ, McIntyre BD. 1999. Water management with Leakey R. 1996.Definitionof agroforestryrevisited. hedgerowsystems. In: Agroforestry in Sustainable Agroforestry Today 8(1): 5-7. Agricultural Systems. Lewis Publishers, Florida. p. 47-63. Levia DF, Frost E.E. 2003. A review and evaluation of SmallholderAgroforestryOptionsforDegradedSoils stemflow literature in the hydrologic and (SAFODS). 2003. SAFODS Philippine Team Annual biogeochemical cyclesof forested andagricultural Report.EcoinformaticsLab.,InstituteofBiological ecosystems. J Hydrol 274: 1-29. Sciences, University of the Philippines Los Banos, College, Laguna. 24 p. Liu WY, Fox JED, Xu ZF. 2002. Nutrient fluxes in bulk precipitation,throughfall and stemflowinmontane Sanchez DA. 1987. Soil productivity and sustainability in subtropical moist forest on Ailao Mountains in Yunnan, agroforestry systems.In:Agroforestry: A Decade of South-West China. J Trop Ecol 18: 527-548. Development. Stepp ler HA, Nair PKR, editors. ICRAF, Nairobi. p. 205-226. Marin CT, Bouten W, Sevink J. 2000. Gross rainfall and its partitioning into throughfall, stemflow and evaporation of Shachnovich Y,BerlinerPR,BarP. 2008.Rainfall intercepted water in four forest ecosystems in western interception and spatial distribution of throughfall in a Amazonia. J Hydrol 237: 40-57. pine forest planted in an arid zone. Journal of Hydrology 349: 168-177. Moreno J, GallardoJF, BussottiF. 2001.Canopy modification of atmospheric decomposition in SoilSurvey DivisionStaff (SSDS).1993.SoilSurvey oligotcophic Quercus pyrenaica forests of an unpolluted Manual. Soil Conservation Service, U.S. Department of region (Central Western Spain). Forest Ecol Manag Agriculture Handbook 18. 149: 47-60. Tacio, H.D. 1991. Save the topsoil from erosion. The [MPDC] MunicipalPlanning and Development Council. PCARRD Monitor, 19, No. 5, September-October 1991. 1998. Comprehensive Land Use Planof Claveria. Philippine Council for Agricultural Resources Research Claveria, Misamis Oriental. and Development, Los Banos, Philippines. Park A, Cameron JL. 2008. The influence of canopy traits on Tisdale SL, Nelson WL. 1975. Soil Fertility and Fertilizers. throughfall and stemflow in five tropical trees growing in 3rd Ed. New York : Macmillan Publishing Co., Inc., 694 p. a Panamanian plantation. Forest Ecol Manag 255. 1915 -1925. Wang JR, Lectchford T, Comeau P, Kimmins JP. 2000. Above and below-ground biomass nutrient distribution Pattanayak, S.andD.E.Mercer. 1998.Valuingsoil of a paper birch and subalpine for mixed species stand conservation benefits of agroforestry: contour inthe sub-boreal spruce zone of British Columbia. hedgerows in theEasternVisayas, Philippines. Forest Ecol Manag 147: 17-26. Agricultural Economics 18 (1): 31-46. Waring RH, Running SW. 1999. Forest Ecosystem. 2nd Pedersen LB, Hansen JB. 1999. A comparison of litterfall Ed.USA, Academic Press, 101 p. and element fluxes in even-aged Norway spruce, sitka spruce and beech stands in Denmark. Forest Ecol Xu X, Wang Q, Hirata E. 2005. Precipitation partitioning and relatednutrientfluxesinasubtropicalforestin Manag 114: 55-70. Okinawa, Japan. Ann For Sci 62(3): 245-252. Rao MR, Sharma MM, Ong CK. 1991. A tree-crop interface Yamoah CF, Burleigh JR. 1992. Alley cropping Sesbania design anditsuse for evaluating the potentialof sesban (L) Merill with food crops in the highland region hedgerow intercropping. Agroforest Sys 13: 143-158. of Rwanda. Agroforest Sys 10(2): 169-181.

44 Growth, productivity, water and nutrient flows in hedgerow systems