Yejin Lee, Hong-Bae Yun, Seong-Soo Kang, Suk-Young Hong, Jong-Sik Lee, Deog-Bae Lee

Transcription

1 Soil Nutrient Management Based on Soil Information System in Korea Yejin Lee, Hong-Bae Yun, Seong-Soo Kang, Suk-Young Hong, Jong-Sik Lee, Deog-Bae Lee Soil and Fertilizer Division, National Academy of Agricultural Science (NAAS), RDA 150 Suin-ro, Gwonseon-gu, Suwon, Gyeonggi-do, , Korea Abstract The Soil Information System (SIS) in Korea has been developed to manage the soil fertility and soil resources for sustaining agricultural production. To manage the fertilization, the fertilizer application rates were established considering soil nutrient contents and crop requirements. The fertilizer recommendation program in the soil information system is based on the fertilization equation by soil testing, and it provides the farmer with soil information such as soil physical and chemical properties, and fertilizer application rates. Through this system, the farmer can apply fertilizers economically, and the soil-testing database can be used to establish the fertilizer supply policy. Keywords: Soil Information System, fertilizer recommendation system. Introduction Soil nutrient management is an important issue for sustainable agricultural production. Fertilizer supply is influenced by the source of agricultural materials, soil fertility in the farmland, cultivation area, and other factors. With increasing costs of agricultural materials, such as fertilizers, and changes in the agricultural environment, a strategic nutrient management in agriculture is required. In Korea, fertilizer application rates that consider the nutrient uptake rate of crop and soil fertility have been established to manage eco-friendly soil fertilization. A fertilizer recommendation system was developed since the 1990s, and web-based system has been provided since This system is connected with the Korean Soil Information System (SIS), which is based on digital soil map and soil physical-chemical properties in the parcel unit. Soil testing data is updated in this system at any time, and it is used to issue the fertilizer prescription. Through the SIS, soil nutrient condition in the country is monitored and used to establish the fertilizer supply policy. This paper discusses the fertilization management in Korea and the fertilizer recommendation program in the Korean SIS. An overview of agriculture and soil fertility in Korea The percentage of arable land in Korea is 16.9% of the nation s total land area. The area of paddy land is about 959,000 ha, upland area is about 738,000 ha. Grain crop is cultivated in about 91% of the total paddy land area and 21% of the total upland area (2011, KOSIS). The area of cultivation under structure, such as plastic film house, has been on the rise due to an increase in the requirement for fresh vegetables throughout the year. Various crops have also been introduced from abroad. Therefore, fertilization management is needed to suit the various conditions of cultivation. Meanwhile, the pattern of fertilizer application is changing due to an increase in the price of agricultural material and types of organic resources. Recently, with the growth of the livestock industry, there is an increase in the animal wastes produced (Fig. 1). The wastes should be addressed by a ban on the dumping of livestock excretions. In agriculture, the concern is on using the manure as inputs in arable land. Accordingly, recycling agriculture using manure and organic materials is considered to solve the problem of livestock manure treatment. The 1 tb191.indd 1 2/5/2014 3:28:22 PM

2 change in inorganic fertilizer consumption rates reflects this situation (Fig.2). Soil chemical properties in Korea have been surveyed to estimate the change in soil fertility from 1999 to This project was carried out through a point survey of the whole country, and soil fertility was surveyed by a rotation in types of cultivation, paddy, upland, orchard, and plastic film house. The changes in soil chemical properties in Korea are summarized in Table 1, Table 2, Table 3, and Table 4. History of soil fertility research in Korea Soil fertility means the potential of crop production by improving soil quality through the application of soil amendments and fertilizer. Soil fertility research has been based on the law of minimum requirement. The paradigms underlying soil fertility research in Korea have undergone considerable reforms because the objectives of agricultural production have changed. Before the 1960s, soil fertility was managed by self-supplied fertilizer such as livestock manure. The modern soil fertility management was studied since soil survey, which was supported by UNDP/ FAO, had started in The NPK fertilization rate for crops was studied during the UNDP/FAO plan. Until the late 1980s, soil fertility research focused on improving crop yield to ensure sufficient food supply through agricultural material inputs, including chemical fertilizer. Since the 1990s, the agricultural system has been intensively changed, and plastic film house areas increased. As a result, fertilizer consumption in the farm increased. Consequently, environmental problems due to massive use of fertilizer inputs became an important issue. Fertilizer application rate was regulated in order to conserve the soil productivity, and soil nutrient balance research was started in the late 1990s. The change in standard fertilization rates from 1950s to 2000s is shown in Table 5. In the 2000s, organic farming and good agricultural practices (GAP) have been developed to contribute to environmental, economic and social sustainability of agricultural production, including safe and healthy food. Recently, the regional-based nutrient balance is being studied to address the prohibition on dumping livestock waste into the sea, and research for reduction of chemical Fig. 1. Livestock manure production rates from 2007 to 2009 Fig. 2. Fertilizer consumption rates from 2007 to tb191.indd 2 2/5/2014 3:28:23 PM

3 Table 1. Change in chemical properties of paddy soils Year Soil ph SOM* Av.P Ex. Cations (cmol c kg -1 ) Av.SiO 2 Sample (1:5) (g kg -1 ) (mg kg -1 ) K Ca Mg (mg kg -1 ) 99 4, , , , Optimum range 5.5~6.5 25~30 80~ ~ ~ ~ ~180 *Soil organic matter Table 2. Change in chemical properties of upland soils Year Soil ph SOM* Av.P Ex. Cations (cmol c kg -1 ) Sample (1:5) (g kg -1 ) (mg kg -1 ) K Ca (mg kg -1 ) '01 1, '05 1, '09 1, Optimum range 6.0~6.5 20~30 300~ ~ ~ ~2.0 Table 3. Change in chemical properties of orchard soils Year Soil ph SOM* Av.P Ex. Cations (cmol c kg -1 ) Sample (1:5) (g kg -1 ) (mg kg -1 ) K Ca (mg kg -1 ) '02 1, '06 1, '10 1, Optimum range 6.0~6.5 25~35 200~ ~ ~ ~2.0 Table 4. Change in chemical properties of plastic-film house soils Year Soil ph EC NO 3 -N SOM Av.P Ex. Cations (cmol c kg -1 ) Sample (1:5) (ds m -1 ) (mg kg -1 ) (g kg -1 ) (mg kg -1 ) K Ca Mg '00 2, '04 1, '08 1, , Optimum range 6.0~ ~200 25~35 350~ ~ ~ ~2.5 3 tb191.indd 3 2/5/2014 3:28:23 PM

4 Table 5. Change in inorganic fertilizer application rates in Korea Crop 1950s 1960s 1970s 1980s 1990s 2000s kg 10a-1 Rices Nitrogen Phosphorus Potassium Upland crops Nitrogen Phosphorus Potassium Field vegetables Nitrogen Phosphorus Potassium Greenhouse Nitrogen vegetables Phosphorus Potassium fertilizer consumption is also being conducted as a government policy. To sustain the environment, bulk blending fertilizer, based on soil testing, was distributed to apply fertilizer as required. However, it wasn t provided effectively because its supply was limited. Customized fertilizer beginning with paddy soil has been supplied to overcome the limitation of bulk blending fertilizer since the late 2000s. It is similar to bulk blending fertilizer, and the fertilizer was based on the fertilizer prescription distributed to each county. Establishment of fertilizer application rates for crops To set up the standard fertilization rates for crops, field experiments were conducted according to the law of diminishing return. Suitable crop yields and amount of fertilizer to be applied were decided. County Agriculture Technology Centers in Korea carried out the experiments, and the results were used to establish the fertilization equation, which is based on soil testing. To supply the N requirements of crops, soil N content should be considered. Soil factors that are related to N, P, and K are applied to the fertilization equation. In paddy soil, N fertilization is affected by available silicate (SiO2) and organic matter content in the soil. Silicate has an effect on the leaf erectness of rice; accordingly, N application rates for rice can be increased (Table 6). In upland soil, a factor in the N fertilization equation is organic matter. Nitrate or electrical conductivity (EC) is used to calculate the N application rates in the plastic-film house soil. EC has a linear relation with nitrate. The factors in K fertilization are exchangeable K and the ratio between exchangeable K and the sum of exchangeable Ca and exchangeable Mg (1N NH4OAc ph 7 extraction). Phosphate fertilization is regulated by available P2O5 (Lancaster method) in the soil. Potassium and phosphate factors are applied to paddy, upland, and plastic-film house soils in common (Table 7). Standardized fertilization and soil testingbased fertilizer recommendation have been provided for major crops and are updated continuously for additional crops, aiming at helping farmers effectively manage the soil nutrients. Established fertilization equations are updated to the Soil Information System. Farmers or all users can check the fertilization rate for a crop through the Web-based Soil Information System. Fertilization recommendation can also be issued by the Local Agricultural Technology and Extension Center, and farmers can use it to get a certification for environmentally-friendly agricultural products (Table 8). The fertilizer recommendation is available for about 109 crops. 4 tb191.indd 4 2/5/2014 3:28:23 PM

5 Table 6. Fertilizer recommendations for paddy rice in Korea Fertilizer Equation for Calculating Fertilizer Rates Nitrogen N (kg 10a -1 ) = SOM Av.SiO 2 (Yield goal : 500 kg 10a -1 ) N (kg 10a -1 ) = SOM Av.SiO 2 (Yield goal : 480 kg 10a -1 ) N (kg 10a -1 ) = SOM Av.SiO 2 (Yield goal : 460 kg 10a -1 ) (Maximum application rates : 15, 13, 11 kg 10a -1, respectively) Phosphorus P 2 (kg 10a -1 ) = (100 - Soil Av. P 2 ) 0.1 (Minimum application rates : 3 kg 10a -1 ) Potassium K 2 O (kg 10a -1 ) = (0.03 CEC - Soil K) 47.1 (Minimum application rates : 3 kg 10a -1 ) Silicate SiO 2 (kg 10a -1 ) = (157 - Soil SiO 2 ) 4.2 (Maximum application rates : 300 kg 10a -1 ) Compost SOM < 20g kg -1 : 1600 kg 10a -1 SOM g kg -1 : 1200 kg 10a -1 SOM > 30g kg -1 : 800 kg 10a -1 Table 7. Factors in fertilization equations by soil testing Fertilizer Paddy Upland Plastic film house Orchard Nitrogen SOM SOM Nitrate SOM Available SiO 2 or electrical conductivity Phosphorus Available P 2 Available P 2 Available P 2 Available P 2 Potassium Exchangeable K Exchangeable K Exchangeable K Exchangeable K Table 8. Number of samples in the soil testing database from 2007 to 2010 Year Total Fertilizer Certification for Products Recommendation Environment-friendly 1) GAP 2) , ,976 (68%) 127,823 (30%) 8,099 (1.9%) , ,277 (64%) 146,369 (32%) 17,823 (3.9%) , ,127 (83%) 144,783 (16%) 13,936 (1.5%) , ,902 (69%) 154,974 (29%) 8,506 (1.6%) 1) Organic, non pesticide, and low level pesticide produce. 2) Good agricultural practices Soil information system in Korea Composition of soil information system SIS is based on the soil survey database. The soil survey was initiated through the collaboration of RDA (Korea), UN and FAO in :250,000 and 1:50,000 scales of soil maps were published from 1964 to Based on the results of the first soil map, the detailed soil survey had been performed in 1990 based on the standards of the Soil Taxonomy of United States Department of Agriculture 5 tb191.indd 5 2/5/2014 3:28:23 PM

6 (USDA). As a result, detailed soil maps (1:25,000) were published. Highly detailed digital soil maps (1:5,000) were made based on survey all over the country from 1995 to Digital soil maps were established using soil survey results through the National Soil Survey Projects from 1998 to All the soil maps were made in a GIS file format. Digital soil maps include the soil survey and soil fertility database of the parcel unit (Table 9). SIS in Korea is open to all users and can be accessed through the Internet at its Web site, soil.rda.go.kr (Fig. 3). The digital soil map in the soil information system is based on highly detailed soil maps (1:5,000) in GIS format. It has soil survey information and soil physical-chemical properties, and is updated regularly. SIS is composed of soil properties in Korea, GIS service of soil environment, fertilizer recommendation system, and statistics about the soil and agriculture environment. Soil attribute information in the digital soil maps consists of 111 properties, such as crop suitability, soil texture (Family), gravel content, drainage class, available soil depth, slope, topography, parent material, land use at the time of soil survey, soil suitability group for paddy, upland, and orchard, as well as soil classification regimes, etc. (Hong et al., 2009) (Table 10). Fertilizer recommendation system The fertilizer recommendation system was started to prevent excessive fertilization and improve the soil fertility through fertilization, considering soil nutrient content and crop nutrient requirement. The fertilizer recommendation was initiated based on the soil testing results by the Arable Lands Development Project (1980~1989). After that, a soil testing laboratory was established in the Local Agricultural Technology and Extension Center, and soil testing database was built from the 1990s. PC-based Fertilizer recommendation program was developed using the soil testing database which had been built by arable lands development project and fertilizer application equation. In 1991, RDA distributed the fertilizer recommendation program ver.1.0 that was possible for rice. And it was upgraded continually by addition of crops which were established the standard of fertilizer application (Table 11). A Web-based fertilizer recommendation system was developed in 2008 to manage the fertilization effectively. This program is composed of fertilizer recommendation and calculator, database management of soil testing, and statistics of soil testing results. The components for fertilizer recommendation are shown in Fig. 4. Soil testing service for farmer is provided by the Local Agricultural Technology and Extension Center in Korea. This system is managed to maintain the analysis technique of soil testing by RDA. Regular monitoring of soil nutrient status through soil testing is useful to ensure that the crops are produced sustainably. The process of soil testing is shown in Fig. 5. The fertilizer recommendation sheet contains soil series, texture, drainage condition in the field and optimal range of soil chemical properties, such as ph, EC, organic matter, available P 2, exchangeable cations, and so on. The amounts of fertilizer are calculated based on soil testing results to come up with the recommended inorganic Table 9. Characteristics of soil map and soil fertility database Soil Map Database Soil Fertility Database Characteristics Morphological, physical, and chemical Chemical properties of top soil characteristics from topsoil to subsoil Sampling Unit Soil boundary Each field with parcel information Purpose Soil survey Soil testing Utilization Land use recommendation, crop Fertilizer recommendation suitability, land suitability DB Spatial database Non-spatial database Data form A variety scale of soil map Greater than 6.9 million - 1:250,000, 1:50,000, 1:25,000, 1:5,000 samples (since 1980) 6 tb191.indd 6 2/5/2014 3:28:24 PM

7 Fig 3. The main page of Soil Information System in Korea Table 10. Soil attributes in the Soil Information System Soil theme maps Morphological and physical maps Morphological and physical maps No. of Soil attributes attributes 10 Soil texture, drainage class, available depth, slope, gravel content, soil color, soil erosion grade, parent material, etc. 6 Soil texture, drainage class, available depth, slope, gravel content, soil color, soil erosion grade, parent material, etc. Land use and soil type 4 Land use, land use recommendation (paddy field, dry field, orchard), soil type (paddy field, dry field, forest), etc. Soil classification and land 61 Soil order, suborder, topography, deposition form Crop suitability maps 5 Apple, pear, mandarin orange, water melon, grapes, strawberry, tomato, cucumber, cabbage, etc. Soil suitability maps 25 Paddy field, dry field, orchard, grass, forest soils fertilizer. Soil amendments are recommended to correct the ph in upland soils and supply silicate in the paddy soils. The Fertilizer recommendation report (Fig. 6) for crop cultivation in a parcel unit can be confirmed through the Web site or provided by the Local Agricultural Technology and Extension Center. A smart phone user can connect to the fertilizer recommendation program through mobile page from It is expected to be used in the cultivation field effectively. Recently, customized fertilizer recommendation has been provided to reduce the application rates of inorganic fertilizer and supply the fertilizer that is suitable for soil nutrient content. Types of customized fertilizer are designed from fertilizer application rates by soil testing results. This program has the function of customized fertilizer recommendation for rice cultivation. The statistics for soil properties can also be provided on the Web. 7 tb191.indd 7 2/5/2014 3:28:24 PM

8 Table 11. Development of the fertilization recommendation program Year Program Number of Details crops 1991 PC ver. 1.0 Rice PC issuing and distribution after teaching 1992 PC ver crops Publication of fertilizer recommendation manual 1995 PC ver crops Addition of fertilization standards 1998 PC ver crops Windows95 version, Field management function 2001 Soil management crops Addition of fertilization standards 2002 Soil management crops Calculator of compound fertilizer 2004 Soil management crops Addition of fertilization standards 2007 Soil management crops Addition of fertilization standards 2008 Web-based program 99 crops Web-based fertilizer recommendation program connected with digital soil maps 2012 Web-based program 109 crops Addition of fertilization standards Fig. 4. Components of the fertilizer recommendation program Conclusion Soil Information System (SIS) was developed through the years based on results of the Arable Land Management Project. It contains the highly detailed soil maps, soil environment information, soil testing database, and fertilizer recommendation system. The fertilizer recommendation system has been updated according to the established fertilization equation. Fertilization recommendation is available for 109 crops. Fertilizer application in the SIS considers mainly the soil nutrient content and yield goal. To develop the fertilizer recommendation, this system should be improved to provide the fertilizer application rates required for crop growth due to changes in the environment. In order to do 8 tb191.indd 8 2/5/2014 3:28:24 PM

9 Fig. 5. The process of fertilizer recommendation using Web-based program Fig. 6. Fertilizer recommendation report 9 tb191.indd 9 2/5/2014 3:28:25 PM

10 that, a study will be required to connect the SIS to a crop growth model. The soil information will be uploaded on Web-based SIS, and the database will be helpful in setting up the strategy for soil management. References Hong, S.Y., Y.S. Zhang, B.K. Hyun, Y.K. Sonn, Y.H. Kim, S.J. Jung, C.W. Park, K.C. Song, B.C. Jang, E.Y. Choe, Y.J. Lee, S.K. Ha, M.S. Kim, J.S. Lee, G.B. Jung, B.G. Ko, and G.Y. Kim An introduction of Korean soil information system. Korean J. of Soil Sci. Fert. 42(1): Korean Statistics Information Service (KOSIS) Agricultural production statistics. Kim, S.C., R.Y. Kim, Y.B. Lee, H.B. Yun, Y.J. Lee and B.C. Jang Integrated plant nutrient supply and management strategies to enhance nutrient use efficiency and crop productivity in Korea FFTC Extension Bulletin 636:1-12. Lee, Y.J., H.B. Yun, J.S. Lee, Y.S. Song, S.Y. Hong, M.S. Kim, S.K. Ha Utilization of the fertilizer prescription program and its development for nutrient management of soil in Korea. ESAFS National Institute of Agricultural Science and Technology (NIAST), RDA Korean soil and environmental information system National Academy of Agricultural Science (NAAS), RDA Fertilizer recommendation (Revised ed.). National Institute of Agricultural Science and Technology (NIAST), RDA An instruction guide for soil and environmental resources information system. National Academy of Agricultural Science (NAAS), RDA The survey of agricultural environment. RDA The study to re-establish the amount and major compositions of manure from livestock. 10 tb191.indd 10 2/5/2014 3:28:25 PM