{"id":4046,"date":"2024-10-21T09:14:49","date_gmt":"2024-10-21T00:14:49","guid":{"rendered":"https:\/\/www.jcam-agri.co.jp\/wordpress\/?post_type=agriculture_science&#038;p=4046"},"modified":"2026-06-26T16:16:44","modified_gmt":"2026-06-26T07:16:44","slug":"%e7%ac%ac731%e5%8f%b7%e3%80%802021-r03-6%e7%99%ba%e8%a1%8c","status":"publish","type":"agriculture_science","link":"https:\/\/www.jcam-agri.co.jp\/en\/agriculture_science\/\u7b2c731\u53f7\u30002021-r03-6\u767a\u884c\/","title":{"rendered":"\u7b2c731\u53f7\u30002021(R03).06\u767a\u884c"},"content":{"rendered":"<p class=\"has-text-color has-link-color wp-elements-93986ef57a5b39a307719b884d3752af\" style=\"color:#0000ee;text-decoration:underline\"><a href=\"\/en\/agriculture_science\/\u7b2c731\u53f7\u30002021-r03-6\u767a\u884c\/#page1\" title=\"\u00a7\u52a0\u91cc\u4e0d\u8db3\u5703\u5834\u3078\u306e\u52a0\u91cc\u80a5\u6599\u5897\u65bd\u306b\u3088\u308b\u5927\u9ea6\u53ce\u91cf\u6027\u306e\u6539\u5584\u5bcc\u5c71\u770c\u8fb2\u6797\u6c34\u7523\u7dcf\u5408\u6280\u8853\u30bb\u30f3\u30bf\u30fc\u8fb2\u696d\u7814\u7a76\u6240\u5357\u5c71\u3000\u6075\">\u00a7\u52a0\u91cc\u4e0d\u8db3\u5703\u5834\u3078\u306e\u52a0\u91cc\u80a5\u6599\u5897\u65bd\u306b\u3088\u308b\u5927\u9ea6\u53ce\u91cf\u6027\u306e\u6539\u5584<br>Toyama Prefectural Technology Center for Agriculture, Forestry and Fisheries<br>Agricultural Research Institute<br>\u5357\u5c71\u3000\u6075<\/a><br><a href=\"\/en\/agriculture_science\/\u7b2c731\u53f7\u30002021-r03-6\u767a\u884c\/#page2\" title=\"\u00a7\u571f\u306e\u306f\u306a\u3057\u2212\u7b2c\uff12\u56de\u3088\u3044\u571f\u306e\u6761\u4ef6\u3000\u7269\u7406\u7684\u6027\u8cea\u2212\u305d\u306e\uff11\u6839\u3092\u652f\u3048\u308b\u571f\u306e\u539a\u307f\u30b8\u30a7\u30a4\u30ab\u30e0\u30a2\u30b0\u30ea\u682a\u5f0f\u4f1a\u793e\u5317\u6d77\u9053\u652f\u5e97 \u6280\u8853\u9867\u554f\u677e\u4e2d\u3000\u7167\u592b\">\u00a7\u571f\u306e\u306f\u306a\u3057\u2212\u7b2c\uff12\u56de<br>\u3088\u3044\u571f\u306e\u6761\u4ef6\u3000\u7269\u7406\u7684\u6027\u8cea\u2212\u305d\u306e\uff11<br>\u6839\u3092\u652f\u3048\u308b\u571f\u306e\u539a\u307f<br>Jcam Agri Co.<br>\u5317\u6d77\u9053\u652f\u5e97\u3000\u6280\u8853\u9867\u554f<br>\u677e\u4e2d\u3000\u7167\u592b<\/a><\/p>\n\n\n\n<p id=\"page1\">\u3000<\/p>\n\n\n\n<p>\u3000<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Increased application of potassium fertilizer to potassium-deficient fields<br>\u306b\u3088\u308b\u5927\u9ea6\u53ce\u91cf\u6027\u306e\u6539\u5584<\/h2>\n\n\n\n<p class=\"has-text-align-right\">Toyama Prefectural Technology Center for Agriculture, Forestry and Fisheries<br>Agricultural Research Institute<br>\u5357\u5c71\u3000\u6075<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Introduction.<\/h3>\n\n\n\n<p>\u3000Toyama Prefecture produces Fibersnow, a six-row barley that is highly regarded by consumers for its suitability for processing. In particular, for high quality and stable production of barley, one of the most important technical measures is the practice of soil preparation and accurate application of basal fertilizer. In soil preparation, the company encourages the active application of compost and other organic matter, calcareous materials, and soil improvement materials. As for the precise application of base fertilizer, side-row fertilization with a controlled-release fertilizer that combines fast-acting base fertilizer and coated urea is widely practiced, and \"LP Barley No. 48\" is mainly used.<\/p>\n\n\n\n<p>\u3000On the other hand, in recent years, in Toyama Prefecture, there have been many fields where basic and important nutrients such as soil pH and exchangeable potassium have fallen below standard values, and the yield of \"Fibersnow,\" barley grown after paddy rice, has been sluggish in some cases.<\/p>\n\n\n\n<p>\u3000Based on these results, we have identified some factors that inhibit high-yield barley cultivation and have developed some measures to improve these factors.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img decoding=\"async\" width=\"403\" height=\"326\" src=\"https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-361.png\" alt=\"\" class=\"wp-image-4054\" srcset=\"https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-361.png 403w, https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-361-300x243.png 300w, https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-361-15x12.png 15w\" sizes=\"(max-width: 403px) 100vw, 403px\" \/><\/figure><\/div>\n\n\n<h3 class=\"wp-block-heading\">Current Soil Chemistry of Barley Plots in Relation to the Number of Ears with Increased Application of Potassium<\/h3>\n\n\n\n<p>\u3000\u5bcc\u5c71\u770c\u5185\u306e\uff21\uff0c\uff22\u4e21\u5730\u533a\u306e2016\u301c2019\u5e74\u7523\u5927\u9ea6\u5703\u5834\u306b\u304a\u3044\u3066\uff0c\u5927\u9ea6\u64ad\u7a2e\u524d\u306b\u4f5c\u571f\u3092\u30b5\u30f3\u30d7\u30ea\u30f3\u30b0\u3057\u3066pH\u3084\u4ea4\u63db\u6027\u5869\u57fa\u542b\u91cf\u306a\u3069\u306e\u571f\u58cc\u5316\u5b66\u6027\u3092\u5206\u6790\u3057\u305f\u3068\u3053\u308d\uff0c\u571f\u58cc\u306e\u4ea4\u63db\u6027\u52a0\u91cc\u304c\u6c34\u7530\u306e\u571f\u58cc\u6539\u826f\u76ee\u6a19\u502415mg\/100g\u3092\u4e0b\u56de\u308b\u5272\u5408\u304c76.3%\u3068\u9ad8\u304f\uff0c\u5703\u5834\u306e\u5e73\u5747\u5024\u306f11.2mg\/100g\u3068\u4f4e\u304f\u306a\u3063\u305f\uff08\u8868\uff11)\u3002<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img decoding=\"async\" width=\"774\" height=\"215\" src=\"https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-356.png\" alt=\"\" class=\"wp-image-4049\" srcset=\"https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-356.png 774w, https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-356-300x83.png 300w, https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-356-768x213.png 768w, https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-356-18x5.png 18w\" sizes=\"(max-width: 774px) 100vw, 774px\" \/><\/figure><\/div>\n\n\n<p>\u3000\u305d\u306e\u5f8c\uff0c\u5927\u9ea6\u5703\u5834\u306b\u52a0\u91cc\u6210\u5206\u91cf\u306720\u301c40kg\/10a\u3092\u5897\u65bd\u3057\uff0c\u571f\u58cc\u4e2d\u306e\u4ea4\u63db\u6027\u52a0\u91cc\u306e\u5909\u5316\u3092\u307f\u305f\u3068\u3053\u308d\uff0c\u5927\u9ea6\u64ad\u7a2e\u524d\u306b\u6bd4\u3079\u53ce\u7a6b\u5f8c\u306e\u4ea4\u63db\u6027\u52a0\u91cc\u542b\u91cf\u304c\u5897\u52a0\u3059\u308b\u3053\u3068\u304c\u308f\u304b\u3063\u305f\uff08\u8868\uff12)\u3002<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img decoding=\"async\" width=\"422\" height=\"236\" src=\"https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-357.png\" alt=\"\" class=\"wp-image-4050\" srcset=\"https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-357.png 422w, https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-357-300x168.png 300w, https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-357-18x10.png 18w\" sizes=\"(max-width: 422px) 100vw, 422px\" \/><\/figure><\/div>\n\n\n<h3 class=\"wp-block-heading\">Increased application of exchangeable potash for stable and high yield<\/h3>\n\n\n\n<p>\u3000Furthermore, in plots with exchangeable potassium in the soil after harvest of less than 20 mg\/100 g, the number of ears of barley harvested in each year of the four-year period tended to decrease with decreasing exchangeable potassium (Figure 1).<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img decoding=\"async\" width=\"532\" height=\"500\" src=\"https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-359.png\" alt=\"\" class=\"wp-image-4052\" srcset=\"https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-359.png 532w, https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-359-300x282.png 300w, https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-359-13x12.png 13w\" sizes=\"(max-width: 532px) 100vw, 532px\" \/><\/figure><\/div>\n\n\n<p>\u3000Therefore, considering the possibility that the lack of exchangeable potassium in the soil may have affected the yield, we conducted a countermeasure test by increasing the amount of potassium component by 20 kg\/10a. As a result, the number of ears increased and sperm seed weight increased in most of the test plots (Figure 2).<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img decoding=\"async\" width=\"836\" height=\"473\" src=\"https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-360.png\" alt=\"\" class=\"wp-image-4053\" srcset=\"https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-360.png 836w, https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-360-300x170.png 300w, https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-360-768x435.png 768w, https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-360-18x10.png 18w\" sizes=\"(max-width: 836px) 100vw, 836px\" \/><\/figure><\/div>\n\n\n<p>\u3000In District A, where this test was conducted, about 80 kg\/10 a of slaked lime was applied, and in District B, about 100 kg\/10 a of bitter lime and 100 kg\/10 a of fermented silica fertilizer were applied as soil improvement materials before plowing. In addition, LP barley No. 48 (nitrogen-phosphate-calcium: 30-9-9), a fertilizer with controlled fertilizer effect, was applied at the time of seeding at 40-48 kg\/10a in lateral strips.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">summary<\/h3>\n\n\n\n<p>\u3000These results indicate that in barley fields with exchangeable potassium in the soil below 20 mg\/100 g, the number of ears and sperm seed weight increased when 20 to 40 kg\/10a of potassium was added to the soil. The potassium chloride fertilizer used in this study was granular potassium chloride, which was applied before tillage. 20 kg\/10 a of potassium chloride was equivalent to 34 kg\/10 a of potassium chloride.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Conclusion<\/h3>\n\n\n\n<p>\u3000In this issue, I have introduced the relationship between barley, one of the key crops in Toyama Prefecture, and exchangeable potassium in the soil.<\/p>\n\n\n\n<p>\u3000It has been nearly 10 years since the deficiency of potassium was pointed out in Toyama Prefecture, especially in medium-coarse-grained paddy soils, which are typical paddy soils in Toyama Prefecture. Potassium is one of the three major elements of fertilizers and is an essential nutrient for crops. It is hoped that crops will absorb potassium not only from fertilizers but also from the soil, leading to stable production of agricultural products, as well as safe and secure agricultural products.<\/p>\n\n\n\n<p>\u3000The contents presented in this paper were conducted as part of a project research entitled \"Development of Diagnostic Methods and Countermeasures for Factors that Inhibit High Yield\" commissioned by the Ministry of Agriculture, Forestry and Fisheries of Japan.<\/p>\n\n\n\n<p id=\"page2\">\u3000<\/p>\n\n\n\n<p>\u3000<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">No Soil - Part 2<br>\u3088\u3044\u571f\u306e\u6761\u4ef6\u3000\u7269\u7406\u7684\u6027\u8cea\u2212\u305d\u306e\uff11<br>\u6839\u3092\u652f\u3048\u308b\u571f\u306e\u539a\u307f<\/h2>\n\n\n\n<p class=\"has-text-align-right\">Jcam Agri Co.<br>\u5317\u6d77\u9053\u652f\u5e97\u3000\u6280\u8853\u9867\u554f<br>\u677e\u4e2d\u3000\u7167\u592b<\/p>\n\n\n\n<p>\u3000In last month's issue, we presented four conditions and their target values for good soil for crop production. From this month onward, each of the four conditions will be explained. In this issue, we will focus on the first condition, \"soil thickness and hardness,\" which is one of the conditions related to the physical properties of soil, and consider its thickness.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">First, let's dig up the soil.<\/h3>\n\n\n\n<p>\u3000In last month's issue, I mentioned that a veteran chef at a famous hotel in Sapporo remarked that he could harvest many delicious potatoes just by looking at the soil. However, I do not have the courage to say such a thing. I don't know what is inside the soil where the roots of the crops grow, even if I stand in the field where the crops are cultivated (the same is true in a home garden) and look at the soil from above. You cannot know what is inside the soil unless you dig it up. First of all, I would like you to choose an area where the crop growth is average in the field and dig the soil by yourself with a shovel.<\/p>\n\n\n\n<p>\u3000\u6398\u308b\u6df1\u3055\u306f\uff11m\u304c\u76ee\u5b89\u3002\u592a\u967d\u3092\u80cc\u4e2d\u306b\u53d7\u3051\u308b\u3088\u3046\u306b\u3057\u3066\u6398\u308b\uff08\u56f3\uff11)\u3002\u305f\u3060\u306a\u3093\u3068\u306a\u304f\u6398\u308b\u306e\u3067\u306f\u306a\u304f\uff0c\u81ea\u5206\u306b\u5bfe\u3057\u3066\u6b63\u9762\u3068\u306a\u3063\u305f\u3068\u3053\u308d\u306f\uff0c\u571f\u306e\u8868\u9762\u304b\u3089\u5782\u76f4\u306b\u58c1\u72b6\u306b\u3059\u308b\u3053\u3068\u306b\u6c17\u3092\u3064\u3051\u308b\u3002\u3053\u306e\u58c1\u72b6\u3068\u306a\u3063\u305f\u3068\u3053\u308d\u3092\u571f\u306e\u300c\u65ad\u9762\u300d\u3068\u3044\u3046\u3002<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img decoding=\"async\" width=\"294\" height=\"306\" src=\"https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-364.png\" alt=\"\" class=\"wp-image-4059\" srcset=\"https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-364.png 294w, https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-364-288x300.png 288w, https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-364-12x12.png 12w\" sizes=\"(max-width: 294px) 100vw, 294px\" \/><\/figure><\/div>\n\n\n<p>\u3000\u571f\u3092\u30b9\u30b3\u30c3\u30d7\u3067\u6398\u3063\u3066\u3044\u308b\u6642\uff0c\u30b9\u30b3\u30c3\u30d7\u304b\u3089\u4f1d\u308f\u3063\u3066\u304f\u308b\u571f\u306e\u786c\u3055\u3084\u611f\u89e6\u3092\u8a18\u61b6\u3057\u3066\u304a\u3044\u3066\u307b\u3057\u3044\u3002\u571f\u3092\u697d\u306b\u6398\u308c\u308b\u304b\u3069\u3046\u304b\u306f\uff0c\u6b21\u56de\u306b\u4e88\u5b9a\u3057\u3066\u3044\u308b\u300c\u571f\u306e\u786c\u3055\u300d\u306e\u6761\u4ef6\u3068\u95a2\u308f\u308a\u304c\u3042\u308b\u304b\u3089\u3060\u3002\u6398\u3063\u3066\u3044\u308b\u9014\u4e2d\u3067\u571f\u304c\u786c\u304f\u3066\u6398\u308c\u306a\u304f\u306a\u308b\u3068\u304b\uff0c\u77f3\u3053\u308d\uff08\u792b\uff1d\u30ec\u30ad\uff09\u304c\u30b4\u30ed\u30b4\u30ed\u51fa\u3066\u304d\u3066\u6398\u308c\u306a\u3044\u3068\u3044\u3046\u3053\u3068\u306b\u306a\u3063\u305f\u3089\uff0c\u305d\u3053\u3067\u4f5c\u696d\u3092\u7d42\u4e86\u3059\u308b\uff08\u56f3\uff12)\u3002<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img decoding=\"async\" width=\"238\" height=\"364\" src=\"https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-366.png\" alt=\"\" class=\"wp-image-4061\" srcset=\"https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-366.png 238w, https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-366-196x300.png 196w, https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-366-8x12.png 8w\" sizes=\"(max-width: 238px) 100vw, 238px\" \/><\/figure><\/div>\n\n\n<h3 class=\"wp-block-heading\">2. soil has two different thicknesses<\/h3>\n\n\n\n<p>\u3000\u571f\u306e\u65ad\u9762\u3092\u773a\u3081\u308b\u3068\uff0c\u65ad\u9762\u306e\u4e0a\u90e8\u306b\u9ed2\u8272\u3092\u5e2f\u3073\u305f\u571f\u306e\u5c64\u3068\uff0c\u305d\u306e\u4e0b\u306b\u9ed2\u8272\u304c\u6d88\u3048\u305f\u5c64\u304c\u3042\u308b\u3053\u3068\u306b\u6c17\u3065\u304f\u3060\u308d\u3046\uff08\u56f3\uff13)\u3002\u3053\u306e\u9ed2\u8272\u3092\u5448\u3057\u305f\u5c64\u306e\u571f\u3092\u8868\u5c64\u571f\uff08\u307e\u305f\u306f\u4f5c\u571f\uff09\u3068\u3044\u3046\u3002\u305d\u306e\u4e0b\u306e\u9ed2\u8272\u304c\u6d88\u3048\u305f\u5c64\u306e\u571f\u304c\u4e0b\u5c64\u571f\uff08\u307e\u305f\u306f\u5fc3\u571f\uff09\u3067\u3042\u308b\u3002\u4e0b\u5c64\u571f\u306f\u8868\u5c64\u571f\u3068\u306e\u5883\u754c\u304b\u3089\u30b9\u30b3\u30c3\u30d7\u3067\u6398\u308c\u306a\u304f\u306a\u3063\u305f\u3068\u3053\u308d\u307e\u3067\u3068\u4fbf\u5b9c\u7684\u306b\u8003\u3048\u308b\u3053\u3068\u306b\u3059\u308b\u3002<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img decoding=\"async\" width=\"428\" height=\"584\" src=\"https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-367.png\" alt=\"\" class=\"wp-image-4062\" srcset=\"https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-367.png 428w, https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-367-220x300.png 220w, https:\/\/www.jcam-agri.co.jp\/wordpress\/wp-content\/uploads\/2024\/10\/image-367-9x12.png 9w\" sizes=\"(max-width: 428px) 100vw, 428px\" \/><\/figure><\/div>\n\n\n<p>\u3000\u4f5c\u7269\u751f\u7523\u306b\u3068\u3063\u3066\u3088\u3044\u571f\u3067\u3042\u308b\u305f\u3081\u306e\u6761\u4ef6\u306e\u4e00\u3064\u3068\u3057\u305f\u571f\u306e\u539a\u307f\u306b\u306f\uff0c\uff12\u3064\u306e\u7a2e\u985e\u304c\u3042\u308b\u3002\u4e00\u3064\u306f\u8868\u5c64\u571f\u306e\u539a\u307f\u3067\u3042\u308b\u3002\u3082\u3046\u4e00\u3064\u306f\uff0c\u6839\u304c\u571f\u306e\u4e2d\u3067\u697d\u306b\u4f38\u3073\u308b\u3053\u3068\u304c\u3067\u304d\u308b\u539a\u307f\u3067\u3042\u308b\u3002\u3053\u306e\u539a\u307f\u306e\u7bc4\u56f2\u3092\u6709\u52b9\u571f\u5c64\u3068\u3044\u3046\uff08\u56f3\uff13)\u3002<\/p>\n\n\n\n<p>\u3000To be a good soil for crop production, the thickness of the surface soil should be about 20 to 30 cm, and the effective soil layer should be at least 50 cm thick. For example, in the cross section of soil shown in Figure 3, the thickness of the surface soil is about 20 cm. The thickness of the subsoil from the boundary to the point where it is too hard to dig is about 30 cm, so when combined with the thickness of the surface soil, the effective soil layer is about 50 cm. Therefore, it can be judged that the soil in Figure 3 just barely meets the two thickness requirements for good soil.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">3. surface soil thickness is closely related to tillage operations<\/h3>\n\n\n\n<p>\u3000The surface soil is the uppermost part of the soil cross-section and is black in color. In arable land, various organic materials are added to the soil surface, including harvest residues after cultivation, roots of crops left in the soil, and compost. These materials are then plowed into the soil by plow tillage and mixed with the soil by rotary tillage. Organic matter mixed with the soil is gradually decomposed by microorganisms in the soil. The part of the organic matter that is not easily decomposed by microorganisms remains in the soil and becomes soil organic matter (humus). Humus is a black complex organic compound that gives the surface soil its black color.<\/p>\n\n\n\n<p>\u3000As the added organic matter is repeatedly incorporated and mixed deeper into the soil, the thickness of the surface soil gradually increases. Thus, the surface soil is affected by human influence. Therefore, if the thickness of the surface soil does not reach 20 cm, which is the lower limit of the target value, it can be increased by actively feeding organic matter such as compost.<\/p>\n\n\n\n<p>\u3000This topsoil is sometimes referred to as crop soil in agricultural terms. However, the thickness of the two is not always the same. The crop layer is the layer of soil within the area where the soil is plowed inverted by the plow. The depth at which the soil is plowed is the thickness of the crop layer.<\/p>\n\n\n\n<p>\u3000The surface soil provides a place for crop roots to establish and absorb nutrients. In other words, this is the soil layer that has the greatest influence on crop growth. Human activities on the soil for crop production are also basically directed to the surface soil. The management of the surface soil is an important factor in determining the crop productivity of a field.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">4. soil thickness that allows roots to grow<\/h3>\n\n\n\n<p>\u3000It is virtually impossible to increase the thickness of the soil that allows roots to grow, i.e., the effective soil layer, through farming operations. As already mentioned, it is possible to artificially improve the thickness of the surface soil. However, the thickness of the subsoil beneath the surface layer cannot be altered by human manipulation unless it is done by civil engineering. The major factors that determine the effective soil layer are a layer of pebbles that roots cannot pass through, bedrock, and dense hard soil. These layers will not move unless they are removed by civil engineering. Therefore, we cannot improve them by farm work.<\/p>\n\n\n\n<p>\u3000Figure 2 shows an example where a large amount of leki is present at about 50 cm from the soil surface, which limits the thickness of the effective soil layer. It is possible to use a machine to determine whether or not there is any rubble in the subsoil layer. However, such exploration is not common. Also, the presence of the hard, difficult-to-excavate soil layer shown in Figure 3 in the soil can basically only be determined by digging.<\/p>\n\n\n\n<p>\u3000The effective soil layer is the soil layer within which the crop roots can spread. If the effective soil layer is too thin, not only will it not be able to adequately support the crop, but it will also limit the area where nutrient water can be absorbed. If the effective soil layer is restricted to a thickness of less than 50 cm, crop growth is inhibited. However, it is quite difficult to artificially increase its thickness.<\/p>\n\n\n\n<p>\u3000<\/p>\n\n\n\n<p>\u3000<\/p>","protected":false},"featured_media":5538,"template":"","agriculture_science_tag":[163],"class_list":["post-4046","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\/4046","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\/5538"}],"wp:attachment":[{"href":"https:\/\/www.jcam-agri.co.jp\/en\/wp-json\/wp\/v2\/media?parent=4046"}],"wp:term":[{"taxonomy":"agriculture_science_tag","embeddable":true,"href":"https:\/\/www.jcam-agri.co.jp\/en\/wp-json\/wp\/v2\/agriculture_science_tag?post=4046"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}