Difference in Biochemical Properties of Soils with Different Periods of Agricultural Practice after Conversion from Paddies to Uplands

Hyen Chung Chun,Sanghun Lee,Dong Hyeok Gong,Ki Youl Jung,Ju Young Cho,Young-Nam Kim,Yong Bok Lee 한국토양비료학회 2021 한국토양비료학회지 Vol.54 No.4

The intrinsic characteristics of soil can be altered by purpose of land use and its history, which would determine the quality and health of the soil. In South Korea, along with the trend of decreasing agricultural land area, land use conversion from paddies to uplands is being promoted to alleviate the oversupply of rice and to improve the self-sufficiency rate of field crops. So far, in order to increase the productivity of crops after land use conversion, various types of soil management have been applied, focusing mostly on chemical properties related to soil fertility rather than biological properties related to soil health. This study was conducted to compare the difference in soil biochemistry of uplands with different periods of land use conversion from paddies, and to investigate the interrelationship between these soil characteristics. In general, there were significant differences in chemical parameters of soils according to the period of soybean cultivation (2, 4, and 10 years) after land use conversion of paddy fields. In Andong region, soil pH, organic matter (OM), total nitrogen (T-N), available phosphate (Av. P), and exchangeable potassium (Ex. K) increased with increase in the period of the land use conversion. Similarly, pH, Av. P, Ex. K, Ex. Ca, Ex. Mg and Org. P were the highest in the 10-year soybean growing uplands. Like the soil chemistry, soil microbial enzyme activities including dehydrogenase (DHA), β-glucosidase (BG), alkaline phosphatase (ALP), and arylsulfatase (AS) differed by the period of agricultural practices since the land use conversion but varying with study areas. Principle component analysis (PCA) showed clear separations of the upland soils with different periods of farming since land use conversion that is highly influenced by soil OM and pH as well as BG and ALP in both areas. With comprehensive interpretation of all results in this study, we predicted that, in both areas, applications of inorganic and organic fertilizers have been continuously performed, thereby improving the soil productivity of uplands converted from paddies following the land use conversion. As such, improved quality of the soils by the land managements could result in a positive effect on the soil health, by enhancing the overall microbial abundance as well as stimulating their functions such as nutrient cycling.

Differences in Soil Chemistry and Microbial Community between the Upland Converted from Paddy and the Existing Soybean Upland

Hyen Chung Chun,Sanghun Lee,Dong Hyeok Gong,Ki Youl Jung,Hyoen Ji Choe,Young-Nam Kim,Yong Bok Lee 한국토양비료학회 2021 한국토양비료학회지 Vol.54 No.4

Change in land use can alter soil chemical properties and microbial community composition that are greatly associated with the soil quality and health. In South Korea, large numbers of paddy areas have recently converted to upland fields, and various types of land management are conducting to improve the soil fertility and productivity. However, lack of studies have been reported to seek out proper soil management in uplands converted from paddies so far, and also there are few studies about soil microbial community and its relationship with soil properties in the agricultural lands. This study aimed to investigate differences in soil chemistry and microbial community structure between upland converted from paddy and existing soybean upland and to evaluate their changes according to the cultivation periods following the land use conversion. As a result, the soil chemistry and microbial community composition varied significantly with various fertilizer treatments including non-fertilizer (NF), inorganic fertilizer (NPK), and a mixture of NPK and compost (NPKC). Additionally, variations in the chemical and biological parameters were influenced by the period of farming practices following the land use conversion. Overall, the major soil factors related to the change in soil chemistry by different fertilizer treatments; in particular, organic matter (OM), available phosphate (Av. P2O5), and exchangeable K (Ex. K). It is likely that such differences in the chemical parameters were closely linked to the change in soil redox condition after the conversion to uplands. This may affect the formation of soil microbial community structure, directly or indirectly, throughout the whole treatments of this study. The indices of abundance/richness including abundance-based coverage estimator (ACE) and Chao and alpha diversity including Shannon and non-parametric Shannon (Np-Shannon) were in the order NPCK > NPK > NF, consistently. Also, the microbial community structure at phylum level was observed in the order of Proteobacteria > Acidobacteria > Actinobacteria > Chloroflexi > Verrucomicrobia > Planctomycetes > Firmicutes in the soils of this study. Among the bacterial phyla, Acidobacteria and Bacteroidetes that are aerobic and play a key role in nutrient cycling were found to increase their population as the cultivation period increased after the conversion of land use. However, despite the increase in such beneficial bacteria abundance related to nutrient cycling through the soil management for 3 years, it seems that the low availability of P in soils of all treatments and severe climatic conditions adversely affected the soybean yield. Therefore, in order to maximize the soil fertility and productivity after conversion from paddies to uplands, it is important to find out proper soil management approaches for each cropland. Also, such land management should be continuously implemented by identifying environmental factors and microbial community structures that are largely related to soil quality and health improvement.

논의 밭전환 연차간 우분시용에 의한 질소공급 및 밭사료작물의 생산력 변화

서종호,김석동 韓國作物學會 2005 Korean journal of crop science Vol.50 No.6

2002년부터 2004년까지 수원의 작물과학원 논포장을 년차간 순차적으로 밭으로 전환하고 또 밭상태에서 우분을 누적투 입하면서 호밀과 옥수수의 윤작을 통하여 질소와 관련된 토양 특성, 작물의 건물수량 및 질소흡수량을 조사하였는데, 주요 결과는 다음과 같다. 논의 밭전환 1년차에는 밭사료작물, 특히 답리작 호밀의 생육과 수량이 현저히 감소하였으며, 그에 따라 우분시용에 의한 무기태질소 등 양분의 이용효율도 현저히 감소하였다. 그러나 전환년차의 증가와 함께 밭사료작물의 수량과 질소흡수량이 증가하였는데, 특히 밭상태에서 전환3년차까지 우분의 누적투입은 토양에의 무기태 질소공급과 더불어 옥수수의 수량, 질소흡수량 및 우분질소 이용률을 계속적으로 증가시켰다. 그 증가는 전환년차 증가에 따른 논토양 자체의 질소공급보다는 주로 우분시용에 의한 토양물리성 개선, 토양탄소 및 무기화 가능한 지력질소(가급태질소) 증가 등 지력증진에 크게 기인하였다. 따라서 전환밭에서 정상적인 밭사료작물의 수량을 얻기 위해서는 전환2년 이상의 기간이 필요하였으며, 이때 우분의 투입은 토양에 무기태질소 공급뿐만아니라 토양유기물 등 지력증진에도 효과적이었으며, 또한 그것이 누적적으로 투입될 때 그 효과가 증가되는 것으로 나타났다. The effect of cattle manure with the rates of 2 and 4 ton l0a-1 for winter rye and summer corn cultivation, respectively, on the dry matter (DM) yield and nitrogen (N) uptake were investigated during successive three-year conversion period from paddy to upland condition in paddy field. The changes in soil properties and soil N sup-plying capacity during repetitive manure application were a1so examined. Growth and DM yield of upland forage crops, especially. winter rye were hindered highly by poor soil condition in the first year after conversion from paddy to upland condition, so apparent recovery of cattle manure N by crops was very low in the first conversion year. But, DM yield and N uptake of upland forage crops were increased linearly by accumulative input of cattle manure along with mineral N enrichment in soil, which also increased apparent recovery of cattle manure-No It seemed that those increases were mainly due to the improvement of soil properties such as soil mineral N, soil organic matter (soil carbon), potentially mineralizable N and bulk density by accumulative input of cattle manure rather than the increase of soil N supply according to accumulative conversion period from paddy to upland condition. It was derived that conversion period from paddy to upland condition over 2 years is needed to obtain proper DM yield in paddy field and accumulative inputs of cattle manure during the conversion period is more influential to the continuous increment of DM yield and N uptake of upland crop as well as of potential N supplying capacity of soil.

농업경영체 등록정보를 이용한 포도와 블루베리의 폐업지원에 따른 작목전환 실태 분석

이현근 ( Lee Hyun-keun ),문한필 ( Moon Han-pil ),명수환 ( Myeong Su-hwan ) 한국식품유통학회 2020 食品流通硏究 Vol.37 No.4

This study investigated the decision-making and crop conversion of beneficiary fruit farmers after applying for the Farm-Closure Assistance(FCA) program using agricultural management registration information. The proportion of converted areas among orchards was 69.4% for field grapes, 44.1% for facility grapes, and 76.4% for blueberries. It implies that the FCA program has played a role of providing restart-up funds to the vulnerable fruit farmers. Other fruits such as peach, plum, grape, and apple are mostly chosen as converting items by the closing farmers. As of 2016, the proportion of the area where items that Farm-Closure Assistance continued to be cultivated in 2019 were 14.4% for field grapes, 15.7% for facility grapes, and 15.6% for blueberries. The percentage of the area where grape cultivation was newly grown in 2019 was 7.2% for field grapes, 10.9% for facility grapes, and 12.7% for blueberries. This study is meaningful in providing implications for overall institutional improvement in order to prevent the balloon effect and moral hazard problem while promoting substantial restructuring of agriculture.

Verification of Phenomenon Explanatory Power of New Concept Model on Time-Series Decrease of Crop Production During Conversion from Paddy to Upland Condition in Paddy Field

Young Dae Choi,Chang-Young Park,Ki-Yuol Jung,Eul-Soo Yun,Jong-Nae Hyun,Jae-Bok Hwang,In-Seok Oh 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

과수 폐업지원의 성과분석 : 생산성, 규모화, 가격과 소득에 미친 영향

문한필(Hanpil Moon),이현근(Hyun-Keun Lee),최미라(Mira Choi),채상현(Sang-Hyen Chai) 한국농업경제학회 2020 農業經濟硏究 Vol.61 No.3

This study empirically analyzed the effect of the Farm-Closure Assistance(FCA) program on productivity, scale, price, and income of fruit farms for the purpose of objective evaluation of its policy performance.T o this end, panel data for the period of 2000-2018 is constructed for 8 items of fruit, and statistical significance of various proxy variables representing the FCA was tested using the random effect model. As results of the analysis, it is found that the FCA contributed to the improvement of the average productivity and scale of the target item, but the long-term effect on the market price or agricultural income of the item is evaluated to be negligible.I t is because the FCA maintains an institutional framework that induces short-term conversion of crops rather than exit of farming. Although there is an effect on short-term adjustment (reduction) of oversupplied items, it is difficult to expect long-term results such as restructuring, supply and demand stability, and competitiveness improvement.O n the other hand, the balloon effect, which is an indirect ripple effect due to the FCA, is statistically significant in terms of productivity and market price, but not so significant in terms of scale or income increase.