Study On Nutrient Diagnosis Index System Of Short-cycle Eucalyptus Grandis Industry Material Plantation

After the implementation of natural forests protection project and returning farmlandto forest project, China vigorously developed short-cycle industrial raw materialsPlantation due to fiber contradiction between supply and demand of raw materials. SichuanProvince cultivated Eucalyptus grandis plantation to the scale of more than one million mu,and achieved good economic, ecological and social benefits in recent decades.Currently, the reach on site selection, provenances selection, cultivation technologyand management techniques of Eucalyptus grandis plantation is correspondingly mere.However, nutrient supply and demand relationship, the interaction of nutrients and therelationship between nutritional status and production capacity on Eucalyptus grandisforest is still unbeknown. So, it has important scientific significance to establish a viablenutrition diagnostic criteria for Eucalyptus grandis plantation nutrient management,scientific fertilization, soil fertility maintenance, reduce waste and environment pressure bystudy on Eucalyptus grandis plantation nutrient thresholds, nutrient balance, nutrientinteraction. On the other hand, it offer reference for nutrient management of otherfast-growing industrial raw material such as poplar, pine etc.Among factors which has impact on plantation production, genetic factors, climaticfactors, topographic and physiographic factors are difficult to be controlled and improvedby human, and management technique factors is little space to increase yield afterproduction base selected. Only nutrient is the most important factors which affectsustainable management of industrial raw material forest. Therefore on the base ofassumption that the other factors except nutrients are controllable or relative controllable,60 standard sample plots are setup by typical sampling method distinguishing differentforest ages, site conditions, growth status in the range of Eucalyptus grandis plantationdistribution in Sichuan which includes Luzhou, Yibin, Leshan, Meishan, Hongya, Pujiang,Pengshan. Xinjin, etc. And in the period from December 2004 to January 2005 are forestproduction, site grade investigated and soil and leaf samples for 11 kinds of essentialnutrient analysis Collected. The results are as follows:1. The correlation analysis and test results between yield and soil physical factor, soilnutrient concentration, foliar nutrient concentration, between soil nutrient concentration and foliar nutrient concentration, among foliar nutrient concentrations shows:Available P, exchangeable Ca, exchangeable Mg, available Fe, available Cu, availableZn in soil and soil pH, soil thickness, soil gravel content are important factors whichimpact production of Eucalyptus grandis plantation, but N, K, Mn and other elements insoil are less restricted due to provided enough.Ca, Mg, P, Fe, B, N, Zn and Cu which are significantly correlative with productionare important foliar nutrient concentration indexes as a signs of nutrient supply andabsorption. In nutrient balance relations, it is more important between Ca, Zn, Cu, P andother elements which high concentration N, Zn, Cu, Mn and low concentration Ca implyhigh forest production.2. The critical concentration at which forest production reach 85%～90% maximumyield can be computed by the quadratic function between forest production factors such asDBH, tree height, individual volume, forest cumulation, etc. and foliar nutrientconcentrations. Calculated and test results are as follows:Because the diagnosis method by the critical concentration is easily affected by age,growth periods, some climatic factors such as precipitation, temperature, humidity, etc. andnutrients interrelations, the diagnosis results have been some obvious misdiagnosis. Thediagnosis results of S, Cu and Zn are not effective; the negative critical concentration of Caand P is obviously inconsistent with fact; the quadratic equations of K, Fe and Mn are notsignificant to less credibility; only half quadratic equations of N and B are significant; thecritical concentrations of Mg whose optimum concentration changes from 17.21 to 17.30g·kg^-1 are consistent to higher reliability.3. Yield groups are divided firstly, and mean value, standard deviation, variationcoefficient and variance of nutrient concentrations and the ratio calculated in differentgroups, choosed factor whose variance ratio between high-yield group and low-yield groupis significant as a diagnostic parameters, and average value of high-yield group as adiagnostic standard. The diagnostic results are as follows:Forty three diagnosis indexes which includes foliar nutrient concentrations of N, P, Fe,B and foliar nutrient concentrations ratios of N/Zn, P/N, P/K, P/Ca, P/Zn, P/B, K/N, K/Zn,Ca/N, Ca/Zn, Ca/Mn, Ca/B, Mg/N, Mg/P, Mg/K, Mg/B, S/N, S/Mg, S/Zn, Cu/N, Cu/P, Cu/K, Cu/Mg, Cu/Zn, Cu/B, Zn/Mg, Fe/N, Fe/P, Fe/K, Fe/Ca, Fe/Mg, Fe/S, Fe/Cu, Fe/Zn,Fe/B, Mn/P, Mn/K, B/N, B/K are selected, and lists the corresponding referenced valueand nutrient diagnostic results (fertilizer order). The results show that N, K, Zn, Fe and Bbehaves mainly relative lack, other nutrients supply relatively adequate at Eucalyptusgrandis plantation in Sichuan.4. Vector figure whose X-axis, Y-axis and Z-axis denote relative nutrient content,relative nutrient concentration and relative dry weight of 100 Eucalyptus grandis leavesrespectively is established to estimate nutrient status by the direction and size of vector andthe results are as follows:Broad nutrient interaction exists in Eucalyptus grandis plantation in Sichuan. N andZn behave consistently dilution domino effect in all sites. K and B be mainly diagnosedantagonistic domino effect and supplied enough. P be mainly diagnosed lack in Pengshanand Leshan. Ca and Mg is lacking mainly in Pengshan, excessive or antagonistic mainlyin Leshan, which is related with superfluous application of FCMP. S absorb excessivelybecause of the acid deposition in every place. Cu shows lacking or diluent in Pengshanbut excessive or antagonistic in other areas. Fe behaves various interactive status butmainly antagonistic in Leshan and dilution domino effect in other areas. Mn shewslacking, diluent and excessive in Pengshan but mainly excessive in other areas.5. Referring to derivation of plant production potential model, Eucalyptus grandisplantation productivity potential model in Sichuan is Y=L/25 C_PQ(T(50-T))^1/2(1-e^bPmultiply from 1 to m C_iY stands for productivity; L for constant concemed with the colony structure of Eucalyptusgrandis plantation; b for constant concerned with influence of annual precipitation onproduction of Eucalyptus grandis plantation; C_P for photic adjustment coefficient; Q forthe total photic radiation; T for the growth environment temperature; P for precipitation; mfor number of nutrient factors concerned with production of Eucalyptus grandis plantation;C_i for influence coefficients some nutrients on production.Referring Richard's production model, the universal relationship model betweenproduction and nutrient, forest age of Eucalyptus grandis plantation is M=M_max(1-e⁽-bt(X_max-X)X)^1/2/X₀)^cThe dependent variable, M, indicates practical productivity. The independent variable, Xand t, means nutrient concentration and forest age. The parameter, M_max, X₀ and X_max,indicates the maximal productivity(325.12828m³Â·hm^-1), the fittest and the highest nutrientconcentration respectively. The line shape controls parameter, c, equals to 3.37551. The"b", a constant which is related with nutrient characteristic, changes from 0.20 to 0.35.6. The relationship models between soil nutrients and foliar nutrients, foliar nutrientsand foliar nutrients are as follows:â–³C_å…¨N=-0.2376+1.2374â–³C_叶Nâ–³C_å…¨P=0.09510+0.4702â–³C_叶P-0.2266â–³C_叶Mn+0.6641â–³C_叶Bâ–³C_å…¨K=0.7480+0.3430â–³C_叶Mg-0.009094â–³C_叶Mnâ–³C_å…¨Ca=0.2954+1.1952â–³C_叶Ca-0.4903â–³C_叶Mnâ–³C_å…¨Mg=0.2128+â–³1.1004â–³C_叶Mg-3133â–³C_叶Mnâ–³C_å…¨Fe=1.5985-0.4395â–³C_叶S-0.1591â–³C_叶Mnâ–³C_å…¨Mn=0.7074+0.4320â–³C_叶Mg-0.1394â–³C_叶Mnâ–³C_å…¨C=-2.2852+3.2852â–³C_叶Nâ–³C_有N=0.3702+0.6298â–³C_叶Pâ–³C_有P=-6.3989+3.1729â–³C_叶N+4.2256â–³C_叶Bâ–³C_有K=1.0117-0.3339â–³C_叶N+0.3222â–³C_叶Pâ–³C_交Ca=-0.1889+1.7024â–³C_叶Mg-0.5135â–³C_叶Mnâ–³C_交Mg=1.7266-0.4712â–³C_叶N+0.5480â–³C_叶Ca-0.8035â–³C_叶Sâ–³C_有Fe=1.9430-1.1587â–³C_叶Mg+0.2157â–³C_叶Mnâ–³C_有Zn=0.2175+0.5967â–³C_叶N+0.1861â–³C_叶Mnâ–³C_有Cu=1.0549+1.1109â–³C_叶N-1.1655â–³C_叶Caâ–³C_叶N=1.2644-0.3829â–³C_å…¨Zn+0.1184â–³C_å…¨Câ–³C_叶P=0.1678+0.6214â–³C_å…¨P+0.3894â–³C_å…¨K-0.1786â–³C_å…¨Caâ–³C_叶Ca=0.9512-0.3075â–³C_å…¨P+0.1538â–³C_å…¨Ca+0.2025â–³C_å…¨Feâ–³C_叶Mg=0.6918+0.3081â–³C_å…¨Mnâ–³C_叶S=1.1838-0.1838â–³C_å…¨Feâ–³C_叶Mn=2.1645-1.1645â–³C_å…¨Pâ–³C_叶B=0.9680+0.0.03204â–³C_å…¨Câ–³C_叶N=0.9937+0.03629â–³C_有P-0.1249â–³C_交Mg+0.09489â–³C_有Cuâ–³C_叶P=0.5993+0.2648â–³C_有N+0.1360â–³C_交Caâ–³C_叶Ca=0.9351+0.1560â–³C_交Mg-0.09112â–³C_有Cuâ–³C_叶Mg=0.8965+0.1035â–³C_交Caâ–³C_叶S=0.7676+0.4901â–³C_有K-0.08116â–³C_交Ca-0.1766â–³C_交Mgâ–³C_叶Mn=1.9496-0.6925â–³C_交Ca-0.2544â–³C_有Cuâ–³C_叶B=0.9767+0.02328â–³C_有P â–³C_叶N=1.0486+0.3605â–³C_叶P-0.4091â–³C_叶Caâ–³C_叶P=0.02631+0.2822â–³C_叶N+0.3480â–³C_叶K+0.4686â–³C_叶Mg-0.1252â–³C_叶Mnâ–³C_叶K=0.4917+0.2392â–³C_叶P+0.2691â–³C_叶Sâ–³C_叶Ca=0.8511-0.3220â–³C_叶N+0.5675â–³C_叶Mg-0.3153â–³C_叶S+0.2188â–³C_叶Cuâ–³C_叶Mg=0.4427+0.2143â–³C_叶P+0.3430â–³C_叶Caâ–³C_叶S=1.2969-0.2970â–³C_叶Caâ–³C_叶Cu=0.3137+0.2101â–³C_叶N+0.3015â–³C_叶Ca+0.4583â–³C_叶S-0.3451â–³C_叶Zn+0.06182â–³C_叶Feâ–³C_叶Zn=1.4872+0.7408â–³C_叶S-1.3186â–³C_叶Cu+0.09052â–³C_叶Feâ–³C_叶Fe=-2.5052-2.8379â–³C_叶K+4.5674â–³C_叶Cu+1.7758â–³C_叶Znâ–³C_叶Mn=2.0720-1.0721â–³C_叶P7. In summary, nutrient characteristic is P lacking, S superfluous, N and Zn dilutiondomino effect, K and Fe antagonistic domino effect in Sichuan Eucalyptus grandisplantation where Ca, Mg and Cu are lacking at middling or low mountain and there is notnutrient limit at plain. Deep soil(＞40cm), fitting soil acidity(5.37～7.07) and lower stoneratio(＜10%) are necessary conditions of stand select in Sichuan Eucalyptus grandisplantation. Nutrient diagnosis should pay attention to nutrients interaction, and Soilnutrient diagnosis should pay attention to exchangeable Ca and Mg, available P, Fe, Cu andZn, gross Ca, Mg, P and Mn in turn. Foliar nutrient diagnosis should pay attention to Ca,Mg, P, Fe, B, N, Zn and Cu in turn. Foliar nutrient balance diagnosis should pay attentionto 10 foliar nutrient ratio such as N/Zn, K/N, K/Zn, Ca/N, Ca/B, Mg/N, Mg/K, Cu/N,Zn/Mg and B/N. The nutrients interaction and the diagnostic criteria are as follows:â‘ Interaction among nutrients are as follows: N, antagonized by Fe, Zn and high Ca,high Mg, can accelerate absorb of P, K, Ca and Mn, yet, high N concentration mightrestrain Mn. P can accelerate absorb of K, Mg and Mn, antagonized by Zn, Fe, high Mn,high K, high Ca and high Mg, moreover high P possibly restrain K, Zn and Fe. Exceptlimit function high K to P, there is not obvious interaction between K and other elements.There is accelerative action between Ca and Mg, low Ca, Mg was active to absorb of Feand Zn, but high Ca, Mg to N, P, Fe, Mn, S and B inversely. S, antagonized by high Ca andhigh Mg, may accelerate Zn. There is antagonistic actions among Cu, Zn, Fe and Mn, suchas high Mn to Fe, high Cu to Zn. Fe might accelerate Cu but restricted by K, B. There areno effects between B and others, but B is restrained easily by high Ca, high Mg and highFe.â‘¡Soil nutrient diagnosis indexes and corresponding diagnosis standards of optimum concentration are as follows: gross N(1.57g·kg^-1), gross P(0.60g·kg^-1), gross K(19.59g·kg^-1),gross Ca(11.55g·kg^-1), gross Mg(51.44g·kg^-1), gross Zn(1.37g·kg^-1), gross Fe(41.62g·kg^-1),gross Mn(0.53g·kg^-1), organic C(16.73g·kg^-1), available N(95.06mg·kg^-1), availableP(5.29mg·kg^-1), available K(65.37mg·kg^-1), exchangeable Ca(2.72g·kg^-1), exchangeableMg(1.52g·kg^-1), available Zn(8.38mg·kg^-1), available Fe(68.75mg·kg^-1), available Mn(33.55mg·kg^-1), available Cu(3.13mg·kg^-1).â‘¢Foliar nutrient diagnosis indexes and corresponding diagnosis standards ofoptimum concentration are as follows: N (19.22g·kg^-1), P(1.44g·kg^-1), K(12.66g·kg^-1), Ca(6.07g·kg^-1), Mg (17.45g·kg^-1), S (2.64g·kg^-1), Cu 11.35mg·kg^-1), Zn (77.17mg·kg^-1), Fe(0.49g·kg^-1), Mn (1.63g·kg^-1), B (44.49mg·kg^-1).â‘£Foliar nutrient concentration ratio diagnosis indexes and corresponding diagnosisstandard of optimum ratio are as follows: N/Zn (249.06), P/N (0.07492), P/K (0.1137),P/Ca (0.2372), P/Zn (18.66), P/B (32.37), K/N (0.6587), K/Zn (164.05), Ca/N (0.3158),Ca/Zn (78.66), Ca/Mn (3.7293), Ca/B (136.44), Mg/N (0.9079), Mg/P (12.12), Mg/K(1.38), Mg/B (392.22), S/N (0.1374), S/Mg (0.1513), S/Zn (34.21), Cu/N (0.0005905),Cu/P (0.007882), Cu/K (0.0008965), Cu/Mg (0.0006504), Cu/Zn (0.1471), Cu/B (0.2551),Zn/Mg (0.004422), Fe/N (0.02541), Fe/P (0.3392), Fe/K (0.03858), Fe/Ca (0.08046),Fe/Mg (0.02799), Fe/S (0.1850), Fe/Cu (43.03), Fe/Zn (6.33), Fe/B (10.98), Mn/P (1.13),Mn/K (0.1286), B/N (0.002315), B/K (0.003514).