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、山藥吸肥特性 山藥對養分的吸收動態與植株鮮重的增長動態相一致。發芽期

，植株生長量小
，對氮、磷
、jiadexishouliangyishao。shuaimanfakeqi
，suizhezhizhushengchangsududejiakuai
，shengchangliangzengjia，duiyangfendexishouliangyesuizhezengjia

，tebieshiduidandexishouliangzengjiajiaoduo。jinrukuaijingshengchangshengqi
，jingyedeshengchangdadaole高峰
，塊莖迅速生長和膨大，對氮、磷、鉀的吸收也達到了高峰。據測定，每生產1000公斤塊莖
，需純氮4.32公斤、五氧化二磷1.07公斤、氧化鉀5.38公斤，所需氮
、磷
、鉀的比例為4∶1∶5。山藥生長前期供給適量的速效氮肥，有利於藤蔓的生長。進入塊莖生長盛期，要重視氮、磷、鉀jia的de配pei合he施shi用yong，特te別bie要yao重zhong視shi鉀jia肥fei的de施shi用yong，以yi促cu進jin塊kuai莖jing的de膨peng大da和he物wu質zhi積ji累lei。生sheng長chang後hou期qi要yao控kong製zhi氮dan肥fei的de施shi用yong量liang，防fang止zhi藤teng蔓man徒tu長chang。山shan藥yao是shi忌ji氯lv作zuo物wu，土tu壤rang中zhong氯lv離li子zi過guo量liang會hui影ying響xiang山shan藥yao生sheng長chang，表biao現xian為wei藤teng蔓man生sheng長chang旺wang盛sheng，塊kuai莖jing產chan量liang降jiang低di
、品質下降、易碎易斷
，不耐貯藏和運輸。因此

，在生產中不宜施用含氯肥料。

    需肥動態：shanyaodeshengyuqijiaochang，xufeilianghenda
，yinci，taxifeixiaojiaochangdeyoujifei。youyukuaijingdexingchengbansuizhedianfendengwuzhidejilei，gulinjiadexuqiuliangxiangduijiaoda。shanyaozaishengchangqianqi
，youyuqiwendi
，youjiyangfenshifangman，yigonggeishiliangdesuxiaodanfei，cujinjingyeshengchang

；shengchangzhonghouqi，kuaijingdeshengchangliangjizeng，xuyaodaliangdeyangfengongying
，yinci，chugonggeizugoudedanfeibaochijingyebushuailaowai，haiyingbushilinjiafei，cukuaijingpengdayuchongshi
，tigaochanlianghepinzhi。yibanshijiangyoujifeiyushiliangdeguolinsuangaiduioufajiaofushuhou
，hunheshiliangjiafeizuodifei，jibennengmanzuquanshengyuduiyangfendexuqiu。zaikuaijingshengchangzhonghouqi
，shizhizhuchangshierzhuishishiliangsuxiaofeiliao，yifangzaoshuai。

    2．山藥營養失調的病害  在zai瘠ji薄bo的de砂sha質zhi土tu壤rang中zhong，因yin養yang分fen供gong應ying不bu足zu，植zhi株zhu生sheng長chang勢shi弱ruo，塊kuai莖jing小xiao，產chan量liang低di，表biao皮pi光guang滑hua，商shang品pin價jia值zhi高gao。在zai水shui肥fei充chong足zu的de黏nian重zhong土tu壤rang中zhong，產chan量liang雖sui高gao
，但dan塊kuai莖jing上shang須xu根gen多duo，易yi發fa生sheng偏pian頭tou、權根現象
，嚴重影響產品的品質。若連作一年造成土壤養分失調而降低產量30%以上，病害加重，且易產生塊莖腐爛，表皮粗厚，顏色變暗，品質差。使肥過多，尤其施用未腐熟的糞肥
，會燒根或塊莖易分杈。