Upland Field Research Articles

Sediment trap efficiency of paddy fields at the watershed scale in a mountainous catchment in northwest Vietnam

Abstract. Composite agricultural systems with permanent maize cultivation in the uplands and irrigated rice in the valleys are very common in mountainous southeast Asia. The soil loss and fertility decline of the upland fields is well documented, but little is known about reallocation of these sediments within the landscape. In this study, a turbidity-based linear mixed model was used to quantify sediment inputs, from surface reservoir irrigation water and from direct overland flow, into a paddy area of 13 ha. Simultaneously, the sediment load exported from the rice fields was determined. Mid-infrared spectroscopy was applied to analyze sediment particle size. Our results showed that per year, 64 Mg ha−1 of sediments were imported into paddy fields, of which around 75 % were delivered by irrigation water and the remainder by direct overland flow during rainfall events. Overland flow contributed one-third of the received sandy fraction, while irrigated sediments were predominantly silty. Overall, rice fields were a net sink for sediments, trapping 28 Mg ha−1 a−1 or almost half of total sediment inputs. As paddy outflow consisted almost exclusively of silt- and clay-sized material, 24 Mg ha−1 a−1 of the trapped amount of sediment was estimated to be sandy. Under continued intensive upland maize cultivation, such a sustained input of coarse material could jeopardize paddy soil fertility, puddling capacity and ultimately food security of the inhabitants of these mountainous areas. Preventing direct overland flow from entering the paddy fields, however, could reduce sand inputs by up to 34 %.

Duration-Related Variations in Archaeal Communities after a Change from Upland Fields to Paddy Fields.

Archaea substantially contribute to global geochemical cycling and energy cycling and are impacted by land-use change. However, the response of archaeal communities to a change from upland field to paddy field has been poorly characterized. Here, soil samples were collected at two depths (0-20 cm and 20-40 cm) from one upland field and six paddy fields that were established on former upland fields at different times (1, 5, 10, 20, 30, and 40 years before the study). Barcoded pyrosequencing was employed to assess the archaeal communities from the samples at taxonomic resolutions from phylum to genus levels. The total archaeal operational taxonomic unit (OTU) richness showed a significant positive correlation with the land-use change duration. Two phyla, Euryarchaeota and Crenarchaeota, were recorded throughout the study. Both the relative abundance and OTU richness of Euryarchaeota increased at both depths but increased more steadily at the subsurface rather than at the surface. However, these data of Crenarchaeota were the opposite. Additionally, the archaeal composition exhibited a significant relationship with C/N ratios, total phosphorus, soil pH, Olsen phosphorus, and the land-use change duration at several taxonomic resolutions. Our results emphasize that after a change from upland fields to paddy fields, the archaeal diversity and composition changed, and the duration is an important factor in addition to the soil chemical properties.

Effect of Biodegradable Mulch Film on Soil Microbial Community

The biodegradable film application can escape from plastic environmental pollution. This experiments studied the effect of biodegradable mulch film on the soil microbial community using fatty acid methyl ester method in soybean production field. The soil NO₃-N content in polyethylene mulch film (PE) soil was significantly higher than biodegradable mulch film soil (p ＜ 0.05). The soil microbial community of Gram negative bacteria showed significantly higher in biodegradable mulch film soil than PE mulch film soil (p ＜ 0.05). In addition, biodegradable mulch film soil had significantly low ratio of cy17:0 to 16:1ω7c and cy19:0 to 18:1ω7c compared with those of PE mulch film soil (p ＜ 0.05), indicating that microbial stress decreased. The ratio of cy17:0 to 16:1ω7c and cy19:0 to 18:1ω7c should be considered as a potential responsible factor for the obvious differentiation that was observed between the biodegradable mulch film soil and PE mulch film soil in a upland field. The results of this experimentation show the potential of using biodegradable mulch film in place of PE.

Effects of Integrated Soil Amelioration Techniques to Mature Newly Established Research Fields

The Rural Development Administration moved to Jeonju for the balanced development of the land. This situation required establishment of new research fields with soils appropriate to cultivation. We applied a variety of amelioration techniques to mature soils of new research fields of the National Institute of Agricultural Science (NAS) and evaluated effects of the integrated amelioration techniques. The schedule of amelioration was following: 1) location of research fields was determined, 2) surface and subsoil samples were collected separately, 3) after aligning the top level of research fields, subsoil and surface soil were re-established with soil amendment, 4) the green manure crops were grown four seasons to improve the uniformity and increase the organic content of the research field, and 5) drainage canal and/or underdrainage were applied to poorly drained fields. The last green manure crop was rape in RDA fields and green barley in NAS fields. The average height, fresh weight, and dry matter weight of rape in good condition were 123 cm, <TEX>$3,938kg\;10a^{-1}$</TEX>, and <TEX>$651kg\;10a^{-1}$</TEX>, respectively. The height, fresh weight, and dry matter of green barley, on average, were 97 cm, <TEX>$3,013kg\;10a^{-1}$</TEX>, and <TEX>$1,004kg\;10a^{-1}$</TEX>, respectively. In the chemical properties of paddy field, pH and levels of silicate, calcium, magnesium, and potassium were in appropriate range but organic matter content of <TEX>$16g\;kg^{-1}$</TEX> was less than the optimum level. In the chemical properties of upland field, pH and levels of phosphorus, calcium, magnesium, and potassium were appropriate range but organic matter content of <TEX>$12g\;kg^{-1}$</TEX> was less than the optimum range. Evaluation of well-adapted soil was performed. The field in RDA was classified into the superior class with points ranging from 90 to 95 by the field evaluation test. The fields in NAS were mainly evaluated as the superior class with points greater than 85. However, some fields in NAS remained low quality with scores between 80 and 83. Further soil amelioration practices were suggested to fields with low soil quality.

Effects of intercropping on soil CO2 and N2O emissions from upland: A review.

Greenhouse gases (GHGs) emission from arable field is a hot topic recently, adopting appropriate cropping systems is an effective way to reduce GHGs emission. This paper reviewed the impacts and mechanisms of intercropping on soil CO2 and N2O emissions in upland field. Rational intercropping systems could increase soil organic carbon (SOC), promote the transformation of straw to SOC, slow down mineralization rate of SOC, and hence reduce soil CO2 emissions. The Poaceae intercropping with legume could maintain the stability of yield while reducing synthetic N inputs, formation of inorganic N by residue decomposition and soil mineral N, and further reducing soil N2O emission. In addition, crop interactions in intercropping system and filed microclimate were important factors on GHGs emission as well. It is necessary to extent the period of researches in field GHGs emission in order to fully understand the underlying mechanisms of GHGs emission in farm land, especially the function of soil microorganisms at molecular level. It would provide theoretical knowledge in building environment-friendly agricultural system in the future.

Nodulation control of crack fertilization technique reduced the growth inhibition of soybean caused by short-term waterlogging at early vegetative stage

Waterlogging is the constraint for soybean growth and yield, because soybean is often cultivated in upland fields converted from paddy in Japan. However, efficient cultivation techniques for alleviating the adverse effects have not been developed. We have proposed the new soybean cultivation technique named crack fertilization which enables yield increase due to enhancing new root growth and N acquisition by increasing nodulation. Waterlogging induces N deficiency due to the suppression of nutrient uptake by the inhibition of root growth and nodule activity. Thus, it is hypothesized that crack fertilization would be effective to alleviate the inhibition of soybean growth and yield. The soybean cultivar of Sachiyutaka was planted in 1/5000 a Wagner pots and root boxes. Two separate waterlogging treatments were imposed to soybean plants at different growth stages, V1 and R4, and crack fertilization was done at V3. After these treatments, soybean plants were sampled at R5 in 2012 and 2013 experiments, respectively. Waterlogging at V1 and R4 inhibited the growth and yield of soybean and nodule growth, and the decreases in physiological parameters of soybean such as photosynthesis, chlorophyll content, and xylem sap exudation rate were observed. The adverse effects of waterlogging at V1 were alleviated by crack fertilization at V3, whereas crack fertilization could not alleviate the adverse effects of waterlogging at R4. Thus, crack fertilization after waterlogging at early vegetative stage would be the cultivation technique that enables to alleviate the adverse effects.

Measuring eco-efficiency of wheat production in Japan: a combined application of life cycle assessment and data envelopment analysis

Wheat is one of the most important cereal crops for human consumption. Understanding the eco-efficiency of wheat production is helpful in achieving sustainable agriculture. In this study, the eco-efficiency of wheat production in Japan at a regional scale was measured using a combined methodology of life cycle assessment and data envelopment analysis. Wheat production in paddy fields with inferior drainage performance was compared with production in upland fields with good growing conditions. The eco-efficiency indicator was defined as wheat yield per single environmental impact index, including global warming as a global environmental category and aquatic eutrophication as a regional one. The results indicate that eco-efficient wheat production can occur in both good and poor growing conditions, with a wheat yield obtained by an adequate application of nitrogen fertilizer. The mitigation of aquatic eutrophication caused by the excessive use of nitrogen fertilizer is an important factor in improving the eco-efficiency of wheat production.

Root hair formation in rice (Oryza sativa L.) differs between root types and is altered in artificial growth conditions.

Root hairs are important sites for nutrient uptake, especially in P limiting conditions. Here we provide first insights into root hair development for the diverse root types of rice grown under different conditions, and show the first in situ images of rice root hairs in intact soil. Roots of plants grown in upland fields produced short root hairs that showed little responsiveness to P deficiency, and had a higher root hair density in the high P condition. These results were reproducible in rhizoboxes under greenhouse conditions. Synchrotron-based in situ analysis of root hairs in intact soil further confirmed this pattern of root hair formation. In contrast, plants grown in nutrient solution produced more and longer root hairs in low P conditions, but these were unequally distributed among the different root types. While nutrient solution-grown main roots had longer hairs compared to upland field-grown main roots, second order lateral roots did not form any root hairs in nutrient solution-grown plants. Furthermore, root hair formation for plants grown in flooded lowland fields revealed few similarities with those grown in nutrient solution, thus defining nutrient solution as a possible measure of maximal, but not natural root hair development. By combining root hair length and density as a measure for root hair impact on the whole soil-grown root system we show that lateral roots provided the majority of root hair surface.

The effects of nitrogen fertilizer application on methane and nitrous oxide emission/uptake in Chinese croplands

AbstractThe application of nitrogen (N) fertilizer to increase crop yields has a significant influence on soil methane (CH4) and nitrous oxide (N2O) emission/uptake. A meta-analysis was carried out on the effect of N application on (i) CH4 emissions in rice paddies, (ii) CH4 uptake in upland fields and (iii) N2O emissions. The responses of CH4 emissions to N application in rice paddies were highly variable and overall no effects were found. CH4 emissions were stimulated at low N application rates (<100 kg N ha−1) but inhibited at high N rates (>200 kg N ha−1) as compared to no N fertilizer (control). The response of CH4 uptake to N application in upland fields was 15% lower than control, with a mean CH4 uptake factor of −0.001 kg CH4-C kg−1 N. The mean N2O emission factors were 1.00 and 0.94% for maize (Zea mays) and wheat (Triticum aestivum), respectively, but significantly lower for the rice (Oryza sativa) (0.51%). Compared with controls, N addition overall increased global warming potential of CH4 and N2O emissions by 78%. Our result revealed that response of CH4 emission to N input might depend on the CH4 concentration in rice paddy. The critical factors that affected CH4 uptake and N2O emission were N fertilizer application rate and the controls of CH4 uptake and N2O emission. The influences of application times, cropping systems and measurement frequency should all be considered when assessing CH4 and N2O emissions/uptake induced by N fertilizer.

A Simple Evaluation System for Microbial Property in Soil and Manure

Analyses of microbial properties in soil and manure had always included the problem that there was no available standard method to evaluate microbial property. The one of the major problems was the vast diversity and the enormous population of soil microorganisms [1], the other was an existence of numerically dominant unculturable microorganisms which comprise 99% of soil habitat [2]. We evaluated whether our newly developed method, by which taxonomies and their number of each bacterial groups were estimated, could be used as evaluation method of microbial properties of soils and manures. In the forest soil, β-Proteobacteria, which included Burkholderia sp., Ralstonia sp., and Alcaligenes sp., was numerically dominant bacteria (3.64 × 106 MPN g-1 dry soil), followed by γ-Proteobacteria (1.32 × 106 MPN), δ-Proteobacteria (0.006 × 106 MPN), and the other gram negative bacteria (0.006 × 106 MPN). In the commercial manure, Actinobacteria, which included Streptoverticillium salmonis, Mycrococcus sp., Streptomyces bikiniensis, and Microbacterium ulmi, was numerically dominant bacterial group (30.8 × 106 MPN), followed by α-Proteobacteria (26.0 × 106 MPN), β-Proteobacteria (17.1 × 106 MPN), δ-Proteobacteria (11.2 × 106 MPN), the other Firmicutes (1.71 × 106 MPN), γ-Proteobacteria (0.5 × 106 MPN), and the other gram negative bacteria (0.05 × 106 MPN). In the upland field, the other Firmicutes, which included Paenibacillus sp., was numerically dominant bacteria (4.41 × 106 MPN), followed by Actinobacteria (2.14 × 106 MPN), Bacillus sp. (2.14 × 106 MPN), and γ-Proteobacteria (0.35 × 106 MPN). Although the precision of the affiliations became lower because of higher diversity of samples and the number of some Antinobacteria and Firmicutes might be underestimated by the used PCR condition, the method was found suitable as a candidate of a new evaluation system of soil and manure.

Water Use for Cultivation Management of Summer-sown Radish in Upland Field on Sand Dune

Water Use for Cultivation Management of Summer-sown Radish in Upland Field on Sand Dune

Development and validation of the SPEC model for simulating the fate and transport of pesticide applied to Japanese upland agricultural soil.

A pesticide fate and transport model, SPEC, was developed for assessing Soil-PEC (Predicted Environmental Concentrations in agricultural soils) for pesticide residues in upland field environments. The SPEC model was validated for predicting the water content and concentrations of atrazine and metolachlor in 5-cm deep soil. Uncertainty and sensitivity analyses were used to evaluate the robustness of the model's predictions. The predicted daily soil water contents were accurate regarding the number of observation points (n=269). The coefficient of determination (R 2) and Nash-Sutcliffe efficiency (NSE ) were equal to 0.38 and 0.22, respectively. The predicted daily concentrations of atrazine and metolachlor were also satisfactory since the R 2 and NSE statistics were greater than 0.91 and 0.76, respectively. The field capacity, the saturated water content of the soil and the Q 10 parameter were identified as major contributors to variation in predicted soil water content or/and herbicide concentrations.

Effects of Narrow-Row Culture by Inter-Row Strip Tillage on the Growth and Yield of Buckwheat（Fagopyrum esculentum Moench）in Upland Field Converted from Paddy Field

Effects of Narrow-Row Culture by Inter-Row Strip Tillage on the Growth and Yield of Buckwheat（<i>Fagopyrum esculentum</i> Moench）in Upland Field Converted from Paddy Field

Wet and Dry Season Effects on Select Soil Nutrient Contents of Upland Farms in North Bank Region of the Gambia

The study was conducted in three villages of North Bank Region of the Gambia in 2013 and 2014. We examined wet and dry season effects on select soil nutrient contents of upland farms in North Bank Region of the Gambia. The objective was to evaluate changes in soil nutrient contents in both wet and dry seasons. Soil samples were collected from three RCBD upland fields with three replications at a depth of 0 - 15 cm and analyzed for pH, Soil Organic Carbon (SOC), and soil moisture content. The gravimetric method of moisture estimation was used. The results showed that soil moisture content, soil TN, and soil pH are significantly different (P < 0.05) during the two seasons. There was no significant difference in SOC between the two seasons in the study area. The study concluded that soil nutrients were more readily available during the wet season than during the dry season probably because there is more soil moisture available in the wet season that facilitates soil nutrient release. The study concludes that soil moisture has to be available in order for some select soil nutrients to be released for plant uptake.

水田転換畑ダイズ作におけるチゼル有芯部分耕を活用した狭畦栽培が生育・収量および雑草抑制に及ぼす影響

秋田県大仙市の水田転換畑において，乾燥・湿害が軽減可能なチゼル型有芯部分耕播種技術を狭畦栽培に活用し，2012年と2013年の6月中旬播種において，2水準の播種密度（標播，疎播）でダイズ品種「リュウホウ」の生育・収量と雑草発生量を検討した．播種密度にかかわらず，チゼル有芯耕狭畦（チゼル狭畦）区では，全層耕標畦（標畦）区と比べて出芽率が有意に高く，雑草発生量は有意に低下したが，倒伏程度は有意に多かった．また，播種密度にかかわらず,チゼル狭畦区の子実収量は標畦・標播区（慣行）と同等であった．チゼル狭畦・疎播区では狭畦により，慣行並にm2当り莢数が増大し，それに伴い子実収量も増加した．以上の結果は，チゼル有芯部分耕は，無中耕・無培土による省力化が可能な狭畦栽培に良く適応でき，慣行の播種量を24％削減した疎播栽培が可能であると推察された．

水田転換畑で栽培されるダイズの欠株に対する収量補償作用

水田転換畑で栽培されるダイズの欠株に対する収量補償作用

지형면과 수문지질단위 분류를 이용한 북한의 지하수 부존량 추정

This study was conducted to provide the preliminary data on preparation for policy decisions regarding the groundwater supply scheme for N. Korea vulnerable to drought. Agricultural activities oriented to upland field due to the mountainous terrain more than 79% as well as the diversity of rainfall distribution over the country make more vulnerable to structural problems in the drought in N. Korea. Therefore, in anticipation of the expansion of exchange policies in agricultural sector, the available amount of groundwater needed for sustainable water resources supply was estimated for each administrative district after analyzing alluvium and hydrogeology distribution in N. Korea. Overall, the available amount of groundwater was estimated to 22.3 billion m³ (0.18 million m³/km²). The available amount of groundwater per unit area in Ryanggangdo and Gaesungsi was appeared very high in each of 0.56 and 0.39 million m³/km², respectively, and it would be interpreted that two districts have relatively wide area of volcanic rocks and alluvium with highly permeable characteristics, respectively. Finally, to maximize the utilization of this study result, the available amount of groundwater distribution map was developed on the basis of the 1 &#xD7; 1 km grid network over the entire N. Korea.

Monitoring for Change of Soil Characteristics by repeated Organic Supply of Comport and Green Manures in Newly reclaimed Organic Upland Field

Monitoring for Change of Soil Characteristics by repeated Organic Supply of Comport and Green Manures in Newly reclaimed Organic Upland Field

Long-term chronological shifts in bacterial communities and hydrolytic extracellular enzyme activities in the forty years following a land-use change from upland fields to paddy fields

Here, we used a forty-year chronosequence of land-use change from upland fields to paddy fields to study short- and long-term temporal patterns in bacterial communities and extracellular enzyme activities (EEAs). Soil samples were collected at two depths (0–20cm and 20–40cm) from one upland field and six paddy fields that were established on former upland fields at different time points (1, 5, 10, 20, 30, and 40 years before the study). 454 barcoded-pyrosequencing was used to identify the bacteria residing in each soil sample. Following the land-use change, bacterial diversity was reduced and bacterial community composition changed in the short-term; however, communities demonstrated a certain level of resilience, returning in structure and composition to states that resembled their original states, prior to land-use change, during the first two decades. In addition, different bacterial responses were observed for the two soil depths. Soil chemical properties were associated with some of these changes; total phosphorus (TP), soil pH and Olsen phosphorus (OP) were significantly correlated with bacterial communities, while both soil pH and nutrient contents significantly affected the EEAs. In addition, we found evidence suggesting associations between EEAs and the abundance of specific bacterial genera, particularly to Chloroflexi and Proteobacteria . Overall, this study provides a temporal view of the bacterial community assembly and functional shifts following land-use change.

Nitrogen fertilization and critical nitrogen concentration for contemporary high yielding cotton under no-tillage

Nitrogen (N) management strategies for cotton may need to be modified because of the use of new high yielding cultivars and improved cropping systems. The objective of this research was to determine the optimal N application rate and critical leaf N concentration for contemporary high yielding cotton under no-tillage systems. A strip-plot trial was conducted on eleven private farms in Crockett, Fayette, Gibson, Haywood, Lake, and Lauderdale counties from 2009 through 2010 in Tennessee. Five N treatments of 0, 45, 90, 134, and 179 kg N ha−1 were evaluated as side-dress N of urea and ammonium nitrate solution in strip plots in a randomized complete block design with three replicates. Eight out of the eleven location–years showed significant yield responses to side-dress N applications. Applying 45–146 kg N ha−1 (including pre-plant and side-dress N) was sufficient for maximum cotton yields at the N responsive location–years. The results of this study indicate that the current N fertilizer recommendations for cotton may be more than adequate for some upland soils but inadequate for some other upland fields. A range of 34.4–47.4 g kg−1 of leaf N concentration at early bloom is required for cotton to reach to maximum lint yield. These critical leaf N values were somewhat greater than the current sufficient N range, which suggests that the current critical leaf N concentrations for cotton in the southern U.S. may need to be modified; contemporary high yielding varieties require slightly higher N application rates to maximize yields.