{"id":4011,"date":"2024-10-21T09:14:10","date_gmt":"2024-10-21T00:14:10","guid":{"rendered":"https:\/\/www.jcam-agri.co.jp\/wordpress\/?post_type=agriculture_science&p=4011"},"modified":"2026-02-16T17:03:00","modified_gmt":"2026-02-16T08:03:00","slug":"%e7%ac%ac732%e5%8f%b7%e3%80%802021-r03-7%e7%99%ba%e8%a1%8c","status":"publish","type":"agriculture_science","link":"https:\/\/www.jcam-agri.co.jp\/en\/agriculture_science\/\u7b2c732\u53f7\u30002021-r03-7\u767a\u884c\/","title":{"rendered":"\u7b2c732\u53f7\u30002021(R03).07\u767a\u884c"},"content":{"rendered":"

\u00a7\u88ab\u8986\u80a5\u6599\u300cJ\u30b3\u30fc\u30c8\u300d\u306e\u6c34\u7a32\u306b\u5bfe\u3059\u308b\u5168\u91cf\u57fa\u80a5\u65bd\u7528\u306e\u52b9\u679c\u3068\u88ab\u819c\u5d29\u58ca\u6027
Agriculture and Forestry Department, Kita-Akita Regional Development Bureau, Akita Prefecture
\u4e3b\u67fb\u3000\u677e\u7530\u3000\u82f1\u6a39
(Former affiliation: Akita Prefectural Agricultural Experiment Station)<\/a>
\u00a7\u571f\u306e\u306f\u306a\u3057\u2212\u7b2c\uff13\u56de
\u3088\u3044\u571f\u306e\u6761\u4ef6\u3000\u7269\u7406\u7684\u6027\u8cea\u2212\u305d\u306e\uff12
\u571f\u306e\u786c\u3055\u306f\u3069\u306e\u3088\u3046\u306b\u3057\u3066\u304d\u307e\u308b\u306e\u304b
Jcam Agri Co.
\u5317\u6d77\u9053\u652f\u5e97\u3000\u6280\u8853\u9867\u554f
\u677e\u4e2d\u3000\u7167\u592b<\/a><\/p>\n\n\n\n

\u3000<\/p>\n\n\n\n

\u3000<\/p>\n\n\n\n

J-Coat\" coated fertilizer on paddy rice
\u5168\u91cf\u57fa\u80a5\u65bd\u7528\u306e\u52b9\u679c\u3068\u88ab\u819c\u5d29\u58ca\u6027<\/h2>\n\n\n\n

Agriculture and Forestry Department, Kita-Akita Regional Development Bureau, Akita Prefecture
\u4e3b\u67fb\u3000\u677e\u7530\u3000\u82f1\u6a39
(Former affiliation: Akita Prefectural Agricultural Experiment Station)<\/p>\n\n\n\n

Introduction<\/h3>\n\n\n\n

\u3000\u88ab\u8986\u80a5\u6599\u306f\uff0c\u5c3f\u7d20\u7b49\u3092\u6a39\u8102\u3084\u786b\u9ec4\u3067\u30b3\u30fc\u30c6\u30a3\u30f3\u30b0\u3057\u305f\u80a5\u6599\u3067\u3042\u308a\uff0c\u7a92\u7d20\u306e\u6eb6\u51fa\u3092\u30b3\u30f3\u30c8\u30ed\u30fc\u30eb\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u308b\u3053\u3068\u304b\u3089\uff0c\u4f5c\u7269\u306e\u751f\u80b2\u306b\u5408\u308f\u305b\u305f\u990a\u5206\u4f9b\u7d66\u3084\u80a5\u6599\u6210\u5206\u306e\u5229\u7528\u7387\u306e\u5411\u4e0a\uff0c\u80a5\u6599\u306e\u65bd\u7528\u56de\u6570\u306e\u524a\u6e1b\u306b\u3088\u308b\u7701\u529b\u5316\u3092\u53ef\u80fd\u306b\u3059\u308b\u6a5f\u80fd\u7684\u306a\u80a5\u6599\u3068\u3057\u3066\u591a\u304f\u306e\u4f5c\u7269\u751f\u7523\u306b\u7528\u3044\u3089\u308c\u3066\u3044\u308b1)<\/sup>\u3002\u4e00\u65b9\uff0c\u88ab\u8986\u80a5\u6599\u306e\u88ab\u819c\u306f\u81ea\u7136\u74b0\u5883\u3067\u751f\u5206\u89e3\u6027\u3084\u5149\u5206\u89e3\u6027\u304c\u3042\u308b\u3082\u306e\u306e\u5168\u3066\u306e\u88ab\u819c\u306e\u5206\u89e3\u306b\u306f\u6642\u9593\u3092\u8981\u3059\u308b\u305f\u3081\uff0c\u6c34\u7a32\u4f5c\u3067\u306f\u80a5\u6599\u6210\u5206\u304c\u6eb6\u51fa\u3057\u305f\u5f8c\uff0c\u6b8b\u3063\u305f\u88ab\u819c\u304c\u4ee3\u304b\u304d\u6c34\u3068\u3068\u3082\u306b\u6c34\u7cfb\u306b\u6d41\u51fa\u3059\u308b\u3053\u3068\u304c\u61f8\u5ff5\u3055\u308c\u3066\u3044\u308b\u3002\u305d\u306e\u305f\u3081\uff0c\u88ab\u819c\u306e\u7cfb\u5916\u6d41\u51fa\u306e\u9632\u6b62\u306b\u5411\u3051\u305f\u751f\u7523\u8005\u3078\u306e\u6ce8\u610f\u559a\u8d77\u306b\u52a0\u3048\uff0c\u81ea\u7136\u74b0\u5883\u4e0b\u3067\u306e\u88ab\u819c\u306e\u5206\u89e3\u6027\u306e\u5411\u4e0a\u3084\u4f7f\u7528\u3059\u308b\u6a39\u8102\u91cf\u306e\u524a\u6e1b\u306a\u3069\u306e\u6280\u8853\u958b\u767a\u3092\u3088\u308a\u4e00\u5c64\u9032\u3081\u308b\u5fc5\u8981\u304c\u3042\u308b2)<\/sup>The following is a list of the most common problems with the \"C\" in the \"C\" column.<\/p>\n\n\n\n

\u3000\u3053\u306e\u3088\u3046\u306a\u80cc\u666f\u3092\u53d7\u3051\uff0c\u8fd1\u5e74\uff0c\u88ab\u819c\u306e\u7cfb\u5916\u6d41\u51fa\u306e\u6291\u5236\u306b\u5bc4\u4e0e\u3059\u308b\u3068\u671f\u5f85\u3055\u308c\u308b\u88ab\u819c\u5d29\u58ca\u6027\u306e\u9ad8\u3044\u88ab\u8986\u80a5\u6599\u300cJ\u30b3\u30fc\u30c8\u300d\u304c\u65b0\u305f\u306b\u958b\u767a\u3055\u308c\u305f\u3002\u672c\u7814\u7a76\u3067\u306f\uff0c2019\u5e74\u30682020\u5e74\u306b\u300cJ\u30b3\u30fc\u30c8\u300d\u306e\u7a92\u7d20\u6eb6\u51fa\u30d1\u30bf\u30fc\u30f3\u3084\u6c34\u7a32\u306e\u751f\u80b2\u53ca\u3073\u53ce\u91cf\u306b\u53ca\u307c\u3059\u5f71\u97ff\uff0c\u6c34\u7a32\uff11\u4f5c\u5f8c\u306e\u88ab\u819c\u5d29\u58ca\u7387\u3092\u660e\u3089\u304b\u306b\u3057\u305f\u306e\u3067\u5831\u544a\u3059\u308b\u3002<\/p>\n\n\n\n

2. Methods<\/h3>\n\n\n\n

\u3000\u8a66\u9a13\u306f\u79cb\u7530\u770c\u8fb2\u696d\u8a66\u9a13\u5834\uff08\u79cb\u7530\u770c\u79cb\u7530\u5e02\u96c4\u548c\u76f8\u5ddd\uff09\u306e\u6c34\u7530\u307b\u5834\uff08\u571f\u58cc\u6761\u4ef6\uff1b\u30b0\u30e9\u30a4\u4f4e\u5730\u571f\uff08\u5e61\u91ce\u7d71)\uff09\u3067\u884c\u3063\u305f\u3002\u4f9b\u8a66\u54c1\u7a2e\u306f\u300c\u3042\u304d\u305f\u3053\u307e\u3061\u300d\u3068\u3057\u305f\u3002\u8a66\u9a13\u533a\u306fJ\u30b3\u30fc\u30c8\u533a\u53ca\u3073LP\u30b3\u30fc\u30c8\u533a\u3092\u5404\uff13\u9023\u8a2d\u7f6e\u3057\uff0c\u6c34\u7a32\u306e\u683d\u57f9\u8a66\u9a13\u306b\u4f9b\u8a66\u3057\u305f\u80a5\u6599\u306f\uff0cJ\u30b3\u30fc\u30c8L70\u53ca\u3073LP\u30b3\u30fc\u30c870\u3092\u542b\u3080\u7c92\u72b6\u914d\u5408\u80a5\u6599\u3067\u3042\u308b\uff08\u8868\uff11) \u30022019\u5e74\u306f\u8015\u8d77\u524d\u306e\uff15\u6708\uff16\u65e5\u306b\uff0c2020\u5e74\u306f\u8015\u8d77\u5f8c\u4ee3\u304b\u304d\u524d\u306e\uff15\u670811\u65e5\u306b10kgN\/10a\u3092\u5168\u5c64\u65bd\u80a5\u3057\u305f\u3002\u683d\u690d\u5bc6\u5ea6\u306f2019\u5e74\u304c21.3\u682a\/\u33a1\uff0c2020\u5e74\u304c22.3\u682a\/\u33a1\u3067\u3042\u3063\u305f\u3002\u8015\u7a2e\u6982\u8981\u306f\u8868\uff12\u306e\u3068\u304a\u308a\u3067\u3042\u308b\u3002<\/p>\n\n\n

\n
\"\"<\/figure><\/div>\n\n
\n
\"\"<\/figure><\/div>\n\n\n

\u3000\u7a92\u7d20\u6eb6\u51fa\u7387\u306f\uff0c\u80a5\u6599\u539f\u4f531g\u3092\u5165\u308c\u305f\u4e0d\u7e54\u5e03\u3092\u65bd\u80a5\u65e5\u306b\u307b\u5834\u306e\u5730\u8868\u9762\u306b\u9759\u7f6e\u3057\uff0c\u8015\u8d77\uff0c\u4ee3\u304b\u304d\u53ca\u3073\u79fb\u690d\u6642\u3092\u9664\u3044\u3066\u7530\u9762\u304b\u30895cm\u306e\u6df1\u3055\u306b\u57cb\u8a2d\uff082019\u5e74\uff15\u9023\uff0c2020\u5e74\uff13\u9023\uff09\u3057\u305f\u3002
\u3000\u307b\u5834\u306e\u5730\u6e29\u306f\uff0c\u65bd\u80a5\u304b\u3089\u576a\u5208\u308a\u307e\u3067\u6e29\u5ea6\u8a18\u9332\u8a08\uff08\u5546\u54c1\u540d\uff1a\u304a\u3093\u3069\u3068\u308aTR-71wf\u578b\uff0c(\u682a)T\uff06D\u88fd\uff09\u30675cm\u6df1\u3092\uff11\u6642\u9593\u9593\u9694\u3067\u6e2c\u5b9a\u3057\u305f\u3002<\/p>\n\n\n\n

\u3000The film collapse rate of the coated fertilizers was investigated using the JCAM method, in which mesh bags containing 100 g of the fertilizer (J-Coat L70 and LP-Coat 70) in 2019 and 50 g in 2020 were buried 5 cm below the rice surface in a row of three, then dug out about 6 months and 11 months after one rice crop, washed and dried, and then evaluated by applying external pressure to the test fertilizer. After washing and drying, the film collapse rate was evaluated by applying external pressure to the test sample fertilizer. The external pressure here was assumed to be the pressure applied at the time of plowing in the year following fertilizer application.<\/p>\n\n\n\n

3. results<\/h3>\n\n\n\n

\u3000J\u30b3\u30fc\u30c8L70\u306e\u7a92\u7d20\u6eb6\u51fa\u306e\u30b9\u30d4\u30fc\u30c9\u306f\uff0c\uff12\u30ab\u5e74\u3068\u3082LP\u30b3\u30fc\u30c870\u3088\u308a\u3082\u9045\u3044\u50be\u5411\u306b\u3042\u3063\u305f\u3002\u7a92\u7d20\u6eb6\u51fa\u7387\u304c80%\u4ee5\u4e0a\u3068\u306a\u3063\u305f\u306e\u306f\uff0cLP\u30b3\u30fc\u30c870\u3067\u306f\uff12\u30ab\u5e74\u3068\u3082\uff17\u6708\u4e0a\u65ec\u3067\u3042\u3063\u305f\u306e\u306b\u5bfe\u3057\u3066\uff0cJ\u30b3\u30fc\u30c8L70\u3067\u306f2019\u5e74\u306f\uff17\u6708\u4e2d\u65ec\uff0c2020\u5e74\u306f\uff17\u6708\u4e0b\u65ec\u3067\u3042\u3063\u305f\uff08\u56f3\uff11)\u3002\u307b\u5834\u306e\u65e5\u5e73\u5747\u5730\u6e29\u306b\u57fa\u3065\u304d\u63a8\u6e2c\u3055\u308c\u308b\u6eb6\u51fa\u7387\u304c80%\u3068\u306a\u308b\u6642\u671f\uff08\u65e5\u5e73\u5747\u5730\u6e29\u304c\u7a4d\u7b97\u30671,750\u2103\u3068\u306a\u308b\u6642\u671f\uff09\u306f\uff0c\u3044\u305a\u308c\u306e\u4f9b\u8a66\u80a5\u6599\u3068\u30822019\u5e74\u3067\u306f\uff17\u6708\u4e0b\u65ec\uff0c2020\u5e74\u3067\u306f\uff18\u6708\u4e0a\u65ec\u3068\u306a\u3063\u305f\u305f\u3081\uff0c\u4e21\u5e74\u306e\u7a92\u7d20\u6eb6\u51fa\u306f\u65e9\u3044\u50be\u5411\u306b\u3042\u3063\u305f\uff08\u56f3\uff12)\u3002<\/p>\n\n\n

\n
\"\"<\/figure><\/div>\n\n
\n
\"\"<\/figure><\/div>\n\n\n

\u3000\u6c34\u7a32\u306e\u7a92\u7d20\u5438\u53ce\u91cf\u306b\u3064\u3044\u3066J\u30b3\u30fc\u30c8\u533a\u3068LP\u30b3\u30fc\u30c8\u533a\u3092\u6bd4\u8f03\u3059\u308b\u3068\uff0c2019\u5e74\u306fJ\u30b3\u30fc\u30c8\u533a\u3067\u4f4e\u304f\u63a8\u79fb\u3057\uff0c2020\u5e74\u306f\u540c\u7b49\u306b\u63a8\u79fb\u3057\u305f\uff08\u56f3\uff11)\u3002J\u30b3\u30fc\u30c8\u533a\u306e\u751f\u80b2\u306f\uff0c2019\u5e74\u306e\u5834\u5408\uff0cLP\u30b3\u30fc\u30c8\u533a\u3088\u308a\u3082\uff16\u6708\u4ee5\u964d\u830e\u6570\u304c\u5c11\u306a\u304f\u63a8\u79fb\u3057\uff0c2020\u5e74\u306e\u5834\u5408\uff0c\u8449\u8272\u304c\u4f4e\u304f\u63a8\u79fb\u3057\u305f\uff08\u56f3\uff13)\u3002\u3053\u308c\u306fJ\u30b3\u30fc\u30c8L70\u306e\u7a92\u7d20\u6eb6\u51fa\u306e\u30b9\u30d4\u30fc\u30c9\u304cLP\u30b3\u30fc\u30c8\u3088\u308a\u3082\u9045\u304b\u3063\u305f\u3053\u3068\u304c\u5f71\u97ff\u3057\u305f\u3068\u8003\u3048\u3089\u308c\u305f\u3002\u53ce\u91cf\uff0c\u53ce\u91cf\u69cb\u6210\u8981\u7d20\u53ca\u3073\u7384\u7c73\u54c1\u8cea\u306b\u3064\u3044\u3066J\u30b3\u30fc\u30c8\u533a\u3068LP\u30b3\u30fc\u30c8\u533a\u3092\u6bd4\u8f03\u3059\u308b\u3068\uff0c\uff12\u30ab\u5e74\u3068\u3082\u7d71\u8a08\u7684\u306b\u6709\u610f\u306a\u5dee\u306f\u306a\u304f\u540c\u7b49\u3067\u3042\u3063\u305f(\u8868\uff13)\u3002<\/p>\n\n\n

\n
\"\"<\/figure><\/div>\n\n
\n
\"\"<\/figure><\/div>\n\n\n

\u3000\u6c34\u7a32\uff11\u4f5c\u5f8c\u306e\u4f9b\u8a66\u80a5\u6599\u306e\u88ab\u819c\u5d29\u58ca\u6027\u306b\u3064\u3044\u3066\uff0c\u5916\u89b3\u3067\u306f\u3044\u305a\u308c\u3082\u660e\u77ad\u3067\u306f\u306a\u3044\u3082\u306e\u306e\uff08\u56f3\uff14)\uff0c\u88ab\u819c\u306b\u5916\u5727\u3092\u52a0\u3048\u3066\u8a55\u4fa1\u3059\u308b\u7802\u4e2d\u5d29\u58ca\u6027\u8a55\u4fa1\u6cd5\uff08JCAM\u6cd5\uff09\u306b\u3088\u308b\u3068\uff0c\u6c34\u7a32\uff11\u4f5c\u5f8c\u306e\u88ab\u819c\u306e\u5d29\u58ca\u306fLP\u30b3\u30fc\u30c8\u3067\u306f\u8a8d\u3081\u3089\u308c\u306a\u304b\u3063\u305f\u306e\u306b\u5bfe\u3057\u3066\uff0cJ\u30b3\u30fc\u30c8\u3067\u306f\uff14\u5272\u7a0b\u5ea6\u306e\u5d29\u58ca\u304c\u8a8d\u3081\u3089\u308c\u305f\uff08\u8868\uff14)\u3002<\/p>\n\n\n

\n
\"\"<\/figure><\/div>\n\n\n

Summary<\/h3>\n\n\n\n

\u3000The effect of full basal application of J-Coat, a newly developed coated fertilizer with an easily collapsible film, on paddy rice plants and its film collapsibility were investigated. The results showed that nitrogen release of J-Coat L70 tended to be slower than that of LP-Coat 70, but the yields were similar. The film collapse rate after one crop of paddy rice was higher than that of LP Coat, indicating that J-Coat L70 contributes to preventing the film from leaching out of the system.<\/p>\n\n\n\n

\u3000However, the results of this study were obtained when all layers were applied in the middle of May. In Akita Prefecture, side-row application of fertilizer at the time of transplanting is widely used, and it is assumed that the timing of application may be in late May. In addition, although the film collapse rate of J-coat was higher than that of LP-coat, it was about 40% after one crop of paddy rice. Further studies on the relationship between the burial period and the film collapse rate, and on the amount of film loss on a field scale, are needed to control the outflow of the film from the system.<\/p>\n\n\n\n

References<\/h3>\n\n\n\n

\uff11\uff09\u4e0a\u91ce\u6b63\u592b\uff0e\u80a5\u52b9\u8abf\u7bc0\u578b\u80a5\u6599\uff08\u88ab\u8986\u80a5\u6599\uff09\u3092\u7528\u3044\u305f\u5b9f\u7528\u7684\u666e\u53ca\u6280\u8853\uff0e
\u3000\u3000\u8fb2\u696d\u3068\u79d1\u5b66\uff0ep.6\u221211(2017\uff09<\/p>\n\n\n\n

\uff12\uff09\u65e5\u672c\u80a5\u6599\u30a2\u30f3\u30e2\u30cb\u30a2\u5354\u4f1a\uff0c\u5168\u56fd\u8907\u5408\u80a5\u6599\u5de5\u696d\u4f1a\uff0e
\u3000\u3000\u6d77\u6d0b\u6f02\u7740\u30d7\u30e9\u30b9\u30c1\u30c3\u30af\u3092\u5de1\u308b\u80a5\u6599\u696d\u754c\u306e\u5bfe\u5fdc\u306b\u3064\u3044\u3066\uff082019\uff09<\/p>\n\n\n\n

\u3000<\/p>\n\n\n\n

\u3000<\/p>\n\n\n\n

\u571f\u306e\u306f\u306a\u3057\u2212\u7b2c\uff13\u56de
\u3088\u3044\u571f\u306e\u6761\u4ef6\u3000\u7269\u7406\u7684\u6027\u8cea\u2212\u305d\u306e\uff12
\u571f\u306e\u786c\u3055\u306f\u3069\u306e\u3088\u3046\u306b\u3057\u3066\u304d\u307e\u308b\u306e\u304b<\/h2>\n\n\n\n

Jcam Agri Co.
\u5317\u6d77\u9053\u652f\u5e97\u3000\u6280\u8853\u9867\u554f
\u677e\u4e2d\u3000\u7167\u592b<\/p>\n\n\n\n

\u3000Last month, we discussed soil thickness in terms of \"soil thickness and hardness,\" one of the four conditions for good soil for crop production, which is related to the physical properties of soil. This month, we will focus on soil hardness.<\/p>\n\n\n\n

1. what determines soil hardness<\/h3>\n\n\n\n

\u3000\u571f\u306b\u306f\u30b9\u30b3\u30c3\u30d7\u3067\u6398\u308b\u3053\u3068\u304c\u3067\u304d\u306a\u3044\u304f\u3089\u3044\u786c\u3044\u571f\u3082\u3042\u308c\u3070\uff0c\u697d\u3005\u3068\u6398\u308b\u3053\u3068\u304c\u3067\u304d\u308b\u571f\u3082\u3042\u308b\u3002\u3044\u3063\u305f\u3044\uff0c\u571f\u306e\u786c\u3055\u306f\u4f55\u306b\u3088\u3063\u3066\u6c7a\u307e\u308b\u306e\u304b\u3002\u57fa\u672c\u7684\u306b\u306f\u300c\u571f\u306e\u7c92\u300d\u306e\u5927\u304d\u3055\uff08\u7c92\u5f84\u3068\u3044\u3046\uff09\u304c\u571f\u306e\u786c\u3055\u3092\u6c7a\u3081\u3066\u3044\u308b\u3002\u571f\u306e\u7c92\uff1f\u3068\u4e0d\u601d\u8b70\u306b\u601d\u3046\u4eba\u304c\u3044\u308b\u304b\u3082\u3057\u308c\u306a\u3044\u3002\u3057\u304b\u3057\uff0c\u7802\u3068\u7c98\u571f\u3092\u601d\u3044\u51fa\u3057\u3066\u307b\u3057\u3044\u3002\u7802\u306f\u30b6\u30e9\u30b6\u30e9\u3057\u3066\u76ee\u3067\u898b\u3066\u4e00\u7c92\u4e00\u7c92\u3092\u78ba\u8a8d\u3067\u304d\u308b\u3002\u3057\u304b\u3057\u7c98\u571f\u306e\u7c92\u306f\uff0c\u76ee\u3067\u898b\u3066\u5927\u304d\u3055\u3092\u78ba\u8a8d\u3067\u304d\u305a\uff0c\u304b\u305f\u307e\u308a\u3067\u3057\u304b\u898b\u3089\u308c\u306a\u3044\u3002<\/p>\n\n\n\n

\u3000When the organic matter contained in the soil is completely removed and only the soil particles are left, the soil is composed of three types of particles: sand (classified into two types: coarse sand and fine sand), clay (clay here does not refer to clay used for clay works but to the very fine soil particles shown in Figure 1), and silt (fine sand), which is intermediate in size between the two. The problem is how much proportion these three types of particles have. The question is what proportion of these three types of particles make up the soil.<\/p>\n\n\n

\n
\"\"<\/figure><\/div>\n\n\n

2. the finer the soil grains, the harder the soil.<\/h3>\n\n\n\n

\u3000If a glass bead is packed in a certain container, the smaller the bead is, the more space it has. If the glass beads are large, they cannot be packed without gaps, and many spaces are created. The term \"denseness\" is used to describe how many particles are packed in a certain volume. The degree of density becomes larger when it is packed with a small glass ball than when it is packed with a large glass ball. Clay has the finest grains, so clayey soil has a high degree of density. On the other hand, sand has coarse grains, so sandy soil has a small degree of density. Therefore, clayey soil is tightly packed into a certain volume and becomes hard soil. Sandy soil with coarse particles does not often produce soil as hard as clayey soil.<\/p>\n\n\n\n

3. how is soil grain size determined?<\/h3>\n\n\n\n

\u3000Then, how is the size of soil grains determined? If soil grain size is innately determined, there would be no difference between sticky soil and sandy soil. Soil grain size is related to the way soil is formed.
\u3000\u571f\u306e\u539f\u6599\u306f\u57fa\u672c\u7684\u306b\u5ca9\u77f3\uff08\u6bcd\u5ca9\uff09\u3067\u3042\u308b\uff08\u706b\u5c71\u7070\u306b\u7531\u6765\u3059\u308b\u9ed2\u30dc\u30af\u571f\u306a\u3069\u306f\u4f8b\u5916)\u3002\u305d\u306e\u5ca9\u77f3\u304c\u98a8\u5316\u4f5c\u7528\u3067\u7d30\u304b\u304f\u7815\u304b\u308c\u3066\u3044\u304f\u3002\u305d\u306e\u7d30\u304b\u304f\u7815\u304b\u308c\u305f\u5ca9\u77f3\u3092\u571f\u306e\u6bcd\u6750\u3068\u3044\u3046\u3002\u571f\u3092\u69cb\u6210\u3059\u308b\u7c92\u5b50\u306e\u5927\u304d\u3055\u306f\uff0c\u539f\u6599\u3068\u306a\u308b\u5ca9\u77f3\u306e\u8cea\u3068\uff0c\u98a8\u5316\u4f5c\u7528\u306e\u5f71\u97ff\u7a0b\u5ea6\u3067\u6c7a\u307e\u308b\u3002\u98a8\u5316\u4f5c\u7528\u306e\u6642\u9593\u3092\u9577\u304f\u7d4c\u9a13\u3057\u305f\u308a\uff0c\u5ca9\u77f3\u304c\u3082\u308d\u304f\u3066\u98a8\u5316\u4f5c\u7528\u3092\u3046\u3051\u3084\u3059\u304b\u3063\u305f\u308a\u3059\u308b\u3068\uff0c\u571f\u306f\u7d30\u304b\u3044\u7c92\u5b50\uff0c\u3059\u306a\u308f\u3061\u7c98\u571f\u3084\u30b7\u30eb\u30c8\u3068\u3044\u3063\u305f\u7c92\u5b50\u304c\u591a\u304f\u306a\u308b\u3002\u305d\u306e\u7d50\u679c\uff0c\u7d30\u7c92\u8cea\u306e\u571f\u304c\u3067\u304d\u308b\u3002\u3053\u306e\u9006\u304c\u7802\u8cea\uff08\u7c97\u7c92\u8cea\uff09\u306e\u571f\u3067\u3042\u308b\u3002\u305d\u306e\u4e2d\u9593\u306e\u72b6\u614b\u304c\u4e2d\u7c92\u8cea\u306e\u571f\u3067\u3042\u308b\u3002<\/p>\n\n\n\n

4. very long time is needed to change the hardness of the soil<\/h3>\n\n\n\n

\u3000The hardness of soil is due to the finer and denser particles of soil. The soil particles contain the time it took for the rocks to break up and for the soil to be formed by the action of living organisms. Thus, it takes a daunting, very long-term effort to essentially soften the hardness of the soil.<\/p>\n\n\n\n

\u3000For example, by feeding coarse organic matter, such as compost, to the soil over many generations, a cushion of organic matter is created in the soil, which gradually softens the soil. In addition, one might think that mixing in sand or other materials would be a good idea. Of course, this is theoretically possible. It may be possible in a small area such as a home garden. However, in a large field, sand must be nearby in large quantities. Sand from the coast is not suitable because of its salinity. It must be river sand. Considering these factors, bringing sand into a fine-grained soil is a picture-perfect and unrealistic idea. It is impossible to change clayey soil into sandy soil.<\/p>\n\n\n\n

5. soil hardness is not determined by soil particles alone<\/h3>\n\n\n\n

\u3000So far, for the sake of simplicity, I have explained soil hardness only in terms of soil particles. However, soil hardness is not that simple. For example, soil hardness varies depending on the moisture content in the same soil. This can be seen from the fact that clay soil becomes hard and hard when it is dried. If such soil is gradually moistened with water, it becomes softer and softer, and finally liquefies into a sludge, which is outside the concept of hardness.
\u3000The nature of soil hardness is very complex, even when we speak of soil hardness in a nutshell. Here we are simplifying the story.<\/p>\n\n\n\n

6. hardness is not the only thing that affects root elongation<\/h3>\n\n\n\n

\u3000Last month and this month we discussed the issue of soil thickness and hardness. This is because we wanted to consider the thickness of the effective soil layer in which roots can grow. However, whether the roots can grow or not is not only determined by the hardness of the soil. There are three factors that inhibit the growth of crop roots. (1) mechanical resistance derived from soil hardness, (2) soil aeration, which indicates whether sufficient air is being pumped into the soil so that root respiration is not adversely affected, and (3) soil moisture conditions. These factors are not independent of each other, but are interrelated, making them even more complex.<\/p>\n\n\n\n

7. Hardness is not an inhibiting factor in general soil<\/h3>\n\n\n\n

\u3000Figure 2 shows the results of an experiment examining the relationship between the above three factors and root elongation. The volumetric weight of 1.0 in Figure 2 indicates that 1 cm3 contains 1 g of dry soil, which is a very normal value for ordinary soil. The increase in volumetric weight can be thought of as the soil particles becoming finer and more cohesive.<\/p>\n\n\n

\n
\"\"<\/figure><\/div>\n\n\n

\u3000\u305d\u3053\u3067\u56f3\uff12\u306b\u3088\u308b\u3068\uff0c\u571f\u306b\u6c34\u305f\u307e\u308a\u304c\u3067\u304d\u308b\u3088\u3046\u306a\u6e7f\u6f64\u72b6\u614b\u3067\u306f\uff0c\u571f\u306e\u4e2d\u306e\u3059\u304d\u9593\u306f\u6c34\u3067\u6e80\u305f\u3055\u308c\u3066\u304a\u308a\uff0c\u571f\u306b\u9178\u7d20\u304c\u4e0d\u8db3\u3059\u308b\uff08\u901a\u6c17\u4e0d\u826f)\u3002\u3053\u306e\u305f\u3081\u571f\u306e\u5bb9\u7a4d\u91cd\u306b\u95a2\u4fc2\u306a\u304f\uff0c\u30a8\u30f3\u30c9\u30a6\u306f\u9178\u7d20\u4e0d\u8db3\u3067\u6839\u3092\u5341\u5206\u306b\u4f38\u3070\u305b\u306a\u3044\u3002
\u3000When there is no puddle and the soil contains some water, mechanical resistance, i.e., soil stiffness, will now inhibit root growth. However, this is the case for slightly fine-grained (clayey) soil with a volume weight of more than 1.1. Ordinary soil with a volume weight of up to 1.0 has water and air in the spaces between the soil, so it is in optimum condition for root growth.<\/p>\n\n\n\n

\u3000When the soil becomes dry, mechanical resistance due to hardness inhibits root elongation in soils with large volumetric weights (fine-grained and clayey). However, in a typical soil with a volume weight of 1.0, mechanical resistance due to hardness does not inhibit root elongation. And, of course, in a soil so dry that the crop wilts, lack of water inhibits root elongation regardless of the volume weight.<\/p>\n\n\n\n

\u3000In other words, it is concluded that soil hardness is a problem in fine-grained soil (clayey soil), and that in general soil hardness itself should not be considered to be an impediment to root growth. For soils with low volumetric weight and light weight, such as black granite soil (soil derived from volcanic ash), soil hardness is hardly a problem. In fact, because of its lightness, black soil is susceptible to wind erosion (soil being blown away by the wind).<\/p>\n\n\n\n

\u3000<\/p>\n\n\n\n

\u3000<\/p>","protected":false},"featured_media":5537,"template":"","agriculture_science_tag":[163],"class_list":["post-4011","agriculture_science","type-agriculture_science","status-publish","has-post-thumbnail","hentry","agriculture_science_tag-163"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.jcam-agri.co.jp\/en\/wp-json\/wp\/v2\/agriculture_science\/4011","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.jcam-agri.co.jp\/en\/wp-json\/wp\/v2\/agriculture_science"}],"about":[{"href":"https:\/\/www.jcam-agri.co.jp\/en\/wp-json\/wp\/v2\/types\/agriculture_science"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.jcam-agri.co.jp\/en\/wp-json\/wp\/v2\/media\/5537"}],"wp:attachment":[{"href":"https:\/\/www.jcam-agri.co.jp\/en\/wp-json\/wp\/v2\/media?parent=4011"}],"wp:term":[{"taxonomy":"agriculture_science_tag","embeddable":true,"href":"https:\/\/www.jcam-agri.co.jp\/en\/wp-json\/wp\/v2\/agriculture_science_tag?post=4011"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}