用眼看 先看是否采用雙層包裝，再看包裝袋上是否標明商標、shengchanxukezhenghaomadengxinxi
，zuihouhaiyaokanneidaishifoufangyouchanpinhegezheng。ruomeiyoucaiyongshuangcengbaozhuanghuobiaoshibuquan，jiyoukenengshiweiliechanpin。nonghudakaineidaishi，haiyaozaixizhakanfuhunfeidekelishifouyizhideng
，ruobuyizhiyehenkenengshiweiliechanpin。

用手摸 用手抓半把複混肥揉搓後，若手上會留有一層灰白色粉末並有黏著感
，其顆粒中可見細小白色晶體的，表明是優質產品；若手上留有一層灰黑色粉末且無黏著感
，顆粒中也無白色晶體，則表明是劣質產品。

用鼻聞 fuhunfeiyibanwuyiwei。ruguoyouyiwei，qieyiweizhong，zekepandingweiliezhifuhunfei。zheyangdefuhunfeishiyonghouqingzeyinqishaomiao，zhongzeshinongzuowujueshou
，erqieduxingcanliushijianchang，huiyingxiangxiachazuowushengchang。

用水溶 youzhifuhunfeishuirongxingjiaohao，jinpaozaishuizhongdabufennengrongjie
，jishiyoushaoliangchendianwu，chendianwuyejiaoxixiao。erliezhifuhunfeizebijiaonanrongyushui，qicanzhacucaoerjianying。

用火燒 取qu少shao量liang複fu混hun肥fei置zhi於yu鐵tie皮pi上shang
，放fang在zai明ming火huo中zhong燒shao灼zhuo，這zhe時shi有you氨an臭chou味wei的de說shuo明ming含han有you氮dan，出chu現xian黃huang色se火huo焰yan的de說shuo明ming含han有you鉀jia。氨an臭chou味wei越yue濃nong，黃huang色se火huo焰yan越yue黃huang
，表biao明ming氮dan、鉀含量越高，即為優質複混肥；反之，則為劣質複混肥。