Effect of added organic matter on soil fertility after stripping-off Cs-contaminated top soil at Iitate village in Fukushima Prefecture

The agricultural fields were contaminated by the radionuclides ¹³⁴Cs and ¹³⁷Cs after the nuclear power plant accident in Fukushima. Prior to the accident, local farmers had successfully established sustainable agriculture in Iitate Village using natural farming practices and recycling. Since 2011, decontamination work such as stripping-off the top soil has been ongoing on agricultural land. Although decontamination is essential, it could cause an unfortunate decrease in soil fertility. Here, we examined the use of organic matter as a means to quickly recover the fertility of the agricultural top soil. We transplanted rice crops into three paddy plots: one received rice straw that had been harvested there last year, another received composted manure, and the third (control) received no additives after decontamination. We applied 40 kg/10a of basal fertilizer and 20 kg/10a of KCl each plot. The rates of Cs concentration in unhulled rice/rice straw were around 0.001. Tendency of plant heights increase and leaf chlorophyll content decrease were similar in the three treatment plots. However, the numbers of stems on 111 days after the transplant were 21, 15, and 19, unhulled rice yield were 513, 462, and 310 g/m², in the rice straw, cattle manure compost, and control plots, respectively. Soil properties of three plots were similar. Radioactive Cs concentrations in the new rice from each treatment plots were lower than the maximum allowed level set by the Japanese government. These results revealed that treating soil with rice straw might have great potential to aid the recovery of a paddy field after stripping-off the top soil. Notably, this treatment significantly improved the yield of rice and supplied organic matter without additional labor.     

Effect of soil exchangeable potassium content on cesium absorption and partitioning in buckwheat grown in a radioactive cesium-contaminated field

The effect of soil exchangeable (plant-available) potassium (ExK) content on cesium (Cs) absorption and translocation in buckwheat was evaluated in a field contaminated with radioactive Cs (¹³⁴Cs and ¹³⁷Cs, RCs) in 2013. The RCs concentration in buckwheat was significantly positively correlated with the naturally occurring stable Cs (¹³³Cs, SCs) concentration, and was lower at higher soil ExK content. The RCs and SCs were actively absorbed by buckwheat until the flowering stage. The soil ExK content was significantly negatively correlated with soil exchangeable RCs and SCs (ExRCs and ExSCs) concentrations. Greater RCs and SCs absorption by buckwheat in soils with low ExK contents was mainly due to higher soil ExRCs and ExSCs concentrations. Reproductive organs showed the largest differences in SCs concentration between low-ExK and high-ExK plots. The root–shoot and shoot–reproductive organs translocations of SCs markedly decreased with increasing soil ExK content. In the root–shoot and shoot–reproductive organs translocations, the discrimination of SCs and K decreased with decreasing soil ExK content. Our main findings were as follows: (1) because RCs are mainly taken up at the earlier growth stage, potassium should be applied as a basal fertilizer to decrease the RCs concentration in buckwheat; (2) lower soil ExK content led to higher soil ExRCs concentrations, resulting in greater RCs absorption by buckwheat; (3) the high Cs absorption and translocation and weaker discrimination between Cs and K in low ExK content soil may be due to the expression of K transporter(s) with weak discrimination between Cs and K.     

Annual Nutrient Balance and Soil Chemical Properties in Heavy Multiple Cropping System in the Coastal Area of Southeast Lake Dianchi,Yunnan Province,China

Abstract

To ensure higher yields, farmers in China have increased cropping intensity with a large input of chemical fertilizer and livestock manure since 1980s, which has led to unsustainable agricultural productivity and environmental quality. This study aimed to evaluate the effects of intensive cropping on nutrient absorption and biomass production of crops and to determine the controllable source of residual nutrients in soil in the coastal area of Lake Dianchi, China. Soil and crops were sampled in 32 vegetable fields and four paddy fields; and simultaneously surveyed. In vegetable fields, cropping intensity and input to each crop were extremely high; and, 58, 72, and 20% of nitrogen, phosphorus, and potassium were not absorbed by the crop. Nitrogen absorption ratios of the vegetables were low. The amount of nitrogen absorbed from sources other than chemical fertilizer by vegetables, namely, from soil, manure, or irrigation water, in the fields with three to nine years cultivation duration was higher than those with zero to two years cultivation duration. Reduction of input should be more efficient than enhancing output to decrease soil nitrogen, phosphorus, and potassium; and, reducing input of chemical fertilizer should be more efficient than reducing input of manure. These results should be helpful for reducing agricultural pollution in China.     

蚯蚓养殖对幼龄胶园土壤养分及橡胶树根系生长的影响

本研究旨在探讨林下蚯蚓养殖对幼龄胶园土壤养分及橡胶树根系生长的影响。以牛粪作为原料，于 2017年4—11 月在 4 年生幼龄胶园铺设粪垄养殖蚯蚓，并测定土壤养分和根系生长情况。结果表明，与对照（CK）相比，铺设粪垄无蚯蚓养殖（WQ）和铺设粪垄蚯蚓养殖（Q）处理总体上可显著提高土壤硝态氮、速效磷、速效钾和土壤水分含量以及土壤 pH，而对土壤铵态氮、有机质、微生物活性及微生物群系数量无显著影响（p<0.05）；和 CK 相比，WQ和 Q 处理显著促进根的生长，并提高吸收根的比例（p<0.05）。综上所述，在幼龄胶园养殖蚯蚓短期内（半年）可提高土壤速效养分含量，促进根系生长。     

蚯蚓养殖对幼龄胶园土壤养分及橡胶树根系生长的影响

本研究旨在探讨林下蚯蚓养殖对幼龄胶园土壤养分及橡胶树根系生长的影响。以牛粪作为原料,于 2017 年 4—11 月在 4 年生幼龄胶园铺设粪垄养殖蚯蚓,并测定土壤养分和根系生长情况。结果表明,与对照（CK）相比,铺设粪垄无蚯蚓养殖（WQ）和铺设粪垄蚯蚓养殖（Q）处理总体上可显著提高土壤硝态氮、速效磷、速效钾和土壤水分含量以及土壤 pH,而对土壤铵态氮、有机质、微生物活性及微生物群系数量无显著影响（p<0.05）;和 CK 相比,WQ和 Q 处理显著促进根的生长,并提高吸收根的比例（p<0.05）。综上所述,在幼龄胶园养殖蚯蚓短期内（半年）可提高土壤速效养分含量,促进根系生长。     

Decreasing radioactive cesium in lodged buckwheat grain after harvest

This study assessed soil contamination with high radioactive cesium (R–Cs) concentration in buckwheat grains by lodging, and assessed the possibility of R–Cs reduction in grain through post-harvest preparation. Analysis of buckwheat grain produced in farmers’ fields and reports from farmers indicated that grain from fields that had lodging showed higher R–Cs than grain from fields with no lodging. A field experiment demonstrated that R–Cs in grain after threshing and winnowing (TW) was about six times higher in lodged plants than in nonlodged plants. In lodged plants, R–Cs in grain was decreased to about one-fourth by polishing, and was decreased to about one-seventh by ultrasonic cleaning, compared with R–Cs in grain after TW. These results demonstrate that R–Cs of buckwheat grain of lodged plants can be decreased by removing soil from the grain surface by polishing and winnowing.     

餐厨废弃物作堆肥在水稻生产中的应用及对土壤环境的影响

为探索餐厨废弃物作堆肥应用于水稻生产过程中的适宜性，设置3组餐厨堆肥用量梯度（15.00 t/hm²、30.00 t/hm²和45.00 t/hm²），并以当地常用的复合肥（0.38 t/hm²）及鸡粪堆肥（13.49 t/hm²）作为施肥对照进行田间小区试验，对不同处理水稻产量、稻米品质、土壤安全性以及经济效益等指标进行测定评价。结果表明，餐厨堆肥处理的水稻产量高于化肥处理，并有效改善了稻米品质;餐厨堆肥处理显著提升了土壤中有机质及速效钾含量，且土壤重金属含量远低于国家标准规定的上限值，属于安全范围;施用15 t/hm²餐厨堆肥处理能够为水稻生产带来正向的经济效益。结果可为餐厨废弃物堆肥化利用提供技术理论支撑。     

Effects of Applying Potassium,Zeolite and Vermiculite on the Radiocesium Uptake by Rice Plants Grown in Paddy FieldSoils Collected from Fukushima Prefecture

Abstract

Radionuclides were released into the environment as a consequence of the Fukushima Daiichi Nuclear Power Plant accident that occurred on 11 March 2011. Radiocesium at an abnormal concentration was detected in brown rice produced in paddy fields located in northern part of Fukushima Prefecture. We examined several hypotheses that could potentially explain the excessive radiocesium level in brown rice in some of the paddy fields, including (i) low exchangeable potassium content of the soil, (ii) low sorption sites for cesium (Cs) in the soil, and (iii) radiocesium enrichment of water that is flowing into the paddy fields from surrounding forests. The results of experiments using pots with contaminated soil indicated that the concentration of radiocesium in rice plants was decreased by applying potassium or clay minerals such as zeolite and vermiculite. The obtained results indicated that high concentrations of radiocesium in rice are potentially a result of the low exchangeable potassium and sorption sites for Cs in the soils. Application of potassium fertilizer and clay minerals should provide an effective countermeasure for reducing radiocesium uptake by plants. Radiocesium-enriched water produced by leaching contaminated leaf litter was used to irrigate rice plants in the cultivation experiments. The results indicated that the radiocesium concentrations in rice plants increased when the radiocesium-enriched water was applied to the potted rice plants. This indicated the possibility that the radiocesium levels in brown rice will increase if the nuclide is transported with water into the rice paddy fields from surrounding forests.     

Effect of rice straw management and organic fertilizer application on growth and yield of dry direct-seeded rice

The objectives of this research were to investigate the effect of rice straw management and application of different types of organic fertilizer on growth and yield of dry direct-seeded rice grown under rainfed conditions. The experiment was conducted in a farmer’s field at Muang Yai village, Khon Kaen province in 2005. A split-plot design was used, with the main plot under rice straw management (incorporating into the soil and burning), and sub-plots by type of organic fertilizer (green manure, cattle manure and powder organic fertilizer) and one plot under no-fertilizer application. It was found that rice straw incorporated into the soil had no significant effect on grain yield when compared with the effect of burning. Organic fertilizer of cattle manure and powder organic fertilizer significantly increased grain yield over that of green manure and no-fertilizer application. This paper is listed as a series of articles of the special issue “Water and Food” 6(1), March 2008.     

黑龙江省玉米施肥现状调查分析

2017年和2018年对黑龙江省大部分地区农户进行施肥现状问卷调查,结果表明,2017年和2018年黑龙江省玉米单位面积产量分别为6415 kg/hm2和6216 kg/hm2.两年农户平均施氮量分别为208 kg/hm2和197 kg/hm2,氮肥偏生产力分别为30.8 kg/kg和31.6 kg/kg,两年农户施氮...     

Differentiating the early impacts of topsoil removal and soil amendments on crop performance/productivity of corn and soybean in eroded farmland of Chinese Mollisols

Farmland soil erosion affects crop productivity. Field experiments were conducted from 2005 to 2006 on a typical Chinese Mollisol at a farm in Hailun, Heilongjiang, China, to differentiate the early impact of topsoil removal on corn and soybean yield, and to determine the effectiveness of soil amendments for restoring the productivity of eroded soils. The simulated erosion levels were established in the autumn of 2004 by removing up to 30 cm of topsoil in 5-cm and 10-cm depth increments. The two soil amendments were: nitrogen, phosphorus, potassium (NPK) chemical fertilizer at the normal farm rate, and NPK chemical fertilizer plus cattle manure. Above-ground dry matter was substantially reduced by topsoil removal at later stages of vegetative growth, while a reduction in root dry mass was observed earlier. Plant height at harvest and photosynthetic rates during reproductive stages were also reduced. Across the 2 years in the normal fertilizer rate, the 5 cm and 10 cm topsoil removal reduced soybean yield by 5% and 9%, and corn yield by 10% and 13% respectively, while 20 cm and 30 cm topsoil removal reduced soybean yield by 37% and 53%, and corn yield by 46% and 73% respectively. Corn was more sensitive to topsoil removal and responded more to application of cattle manure than soybean. The addition of manure did not improve above-ground dry matter accumulation in soybean but greatly increased dry matter in corn in 2006 with a lesser increase in 2005. A significant increase in root growth was found with the addition of chemical fertilizers plus cattle manure in 2006, especially for corn. The addition of cattle manure was an excellent amendment to restore productivity through an enhanced effect on the photosynthetic rate, particularly in corn. Addition of cattle manure with chemical fertilizer restored crop yield in the slightly eroded soil (5 cm topsoil removal). The use of chemical fertilizers with cattle manure for improving crop yields on eroded soils is important in the regions similar to the Chinese Mollisols.     

施钾对小麦/ 玉米产量及土壤钾素平衡的影响

为指导河南小麦/玉米生产中钾肥的合理施用,于2010-2012年在高、中和低三种土壤供钾水平的试验点,研究了施钾量及施钾技术对小麦/玉米轮作产量、钾肥利用效率及土壤钾素平衡的影响。结果表明,在高钾、中钾和低钾土壤上施用钾肥,玉米分别增产4.76%～12.49%、7.56%～16.08%和7.01%～22.61%;小麦分别增产6.87%～13.87%、11.19%～18.57%和18.71%～27.49%。在不同供钾水平土壤上小麦钾肥利用效率均高于玉米,钾肥偏生产力表现为高钾点>中钾点>低钾点,高钾点钾肥当季利用率较高,低钾点的农学效率较高;当施钾量为90、135 kg·hm^-2时,小麦和玉米均以钾肥分2次施用效果较好;施钾量为45 kg·hm^-2时,玉米以底施较好,小麦以追施较好。低钾和中钾点在施钾量大于45 kg·hm^-2时,基本就能维持土壤钾素平衡,而高钾点则在施钾量大于90 kg·hm^-2时土壤钾素才有盈余。综合来看,高、中和低钾点适宜的钾肥用量分别在45、90、135 kg·hm^-2左右,以钾肥分2次施用效果较好。     

无机与有机肥配施对小麦籽粒产量和淀粉糊化特性的影响

为了阐明天田条件下无机与有机肥配施对小麦籽粒产量和品质的调控效应,以中筋型小麦品种豫麦49-198为供试材料,研究了施用有机肥、无机与有机肥配施以及施用尿素处理对小麦籽粒产量和淀粉糊化特性的影响.结果表明,无杌与有机肥配施不仅可以显著提高小麦籽粒产量、蛋白质含量及蛋白质产量.还可以改善小麦淀粉糊化特性.综合各处理结果,施用有机肥以鸡粪处理、无机与有机肥配施以鸡粪+尿素处理对提高小麦籽粒产量、改善小麦淀粉糊化特性的效果较好.     

不同氮肥用量下苦荞灌浆特性及根系形态与充实度变化

以苦荞品种‘晋荞2号’为试验材料,设置不同的氮肥处理,研究了氮肥对苦荞灌浆特性、根系形态、农艺性状、充实度及产量的影响。结果表明:中浓度氮肥处理(MN)对晋荞2号籽粒增重效果最显著;籽粒灌浆过程中的实际百粒重、百粒重理论可能最大值(A)、灌浆起始势(R0)、生长速率为最大时的生长量(Wmax·G)及活跃生长期均以MN处理最高;根系长度、表面积、体积均以MN处理最高,根冠比以低浓度氮肥处理(LN)最高;‘晋荞2号’的农艺性状、充实度及产量各指标基本以LN、MN处理最佳。综上所述,中浓度氮肥处理更利于促进苦荞的灌浆进程,进而提高充实度及产量。本研究为苦荞的高产栽培提供了理论依据和技术支撑。     

SC27微生物土壤增效剂对大麦产量和肥效的影响

为解决浙江嘉兴平原农田土壤氮素过多 ,致使氮素利用率不高的问题 ,从澳大利亚引进SC2 7微生物土壤增效剂 ,研究对大麦产量和肥效的影响。结果表明 :SC2 7对大麦有增穗增粒的作用 ,提高成穗率 ,提高产量。并能改善啤酒大麦的品质 ,有提高N素利用率的作用。其中尤以减氮区 140 2 5kg/hm2 N素和SC2 730 0 0ml/hm2 拌种最为理想。使用SC2 7对改善土壤和保护环境有重大的作用     

嫁接和有机肥对冬瓜生长发育和根际土壤微生物的影响

为了明确不同栽培方式和有机肥施用量对冬瓜生产效应的影响,建立科学合理的栽培模式,本研究通过裂 区设计田间试验,主区为 2 种栽培方式(嫁接栽培和自根栽培),副区为 5 个有机肥施用水平(0、3 750、7 500、11 250、 15 000 kg/hm2 ),研究栽培方式和有机肥施用量对冬瓜生长发育及根际土壤微生物的影响。结果表明：（1）嫁接栽培和 有机肥施用量均能显著影响冬瓜植株干物质重量、产量、果实品质、叶片氮、磷、钾含量及其根际微生物数量。（2） 与自根冬瓜相比,嫁接栽培冬瓜干物质和产量分别平均增加 12.41%和 13.71%;有机酸、可溶性蛋白、维生素 C、可溶 性固性物含量分别平均提高了 33.57%、18.41%、 24.37%和 14.52%;冬瓜叶片氮、磷、钾含量较自根苗冬瓜分别平均 提高了 8.74%、31.02%和 12.06%;嫁接栽培冬瓜根际土壤中放线菌和细菌数量和微生物总量分别平均提高了 16.33%、 28.37%、27.97%,真菌数量减少了 23.62%。（3）无论是嫁接栽培还是自根苗栽培,植株干重、产量、叶片氮磷钾含量、 有机酸含量、可溶性蛋白含量、维生素 C 含量、根际土壤细菌和放线菌数量及总微生物数量均随有机肥施用量的增加 而升高。     

Nitrogen Balance in Forage Rice (Oryza sativa L. cv. Tachisuzuka) Cultivation in Pots with Animal Manure Application

Abstract

Experiments were conducted to evaluate the nitrogen (N) balance in forage rice cultivation using animal manure in 1/2,000a Wagner pots in a greenhouse. The cattle manure and poultry manure were applied at 3 levels of N (0, 14, 28 g available N m^–2) without additional chemical fertilizer application. The pots were designed to simulate the fluid percolation in the paddy field. The results indicated increasing levels of N input improved plant height, tiller number, SPAD value and biomass (straw, grain and root) production, however, N leaching from soil (Andosols) due to percolating water also increased. The planting of rice plants proved to reduce 30% of the N leaching loss. N use efficiency, the ratio of N uptake by plant per unit N application, decreased in higher N application. The N uptake by the above-ground parts occupied about 66% of the whole plants.     

有机肥替代部分无机肥对菜园土理化特性及果实养分的影响

以海南菜园土为试验对象,设计5个不同比例有机肥替代无机肥处理,于2016年11月下旬至2017年5月下旬在海南文昌进行大田试验,探讨有机无机肥不同配比对土壤理化性质和辣椒果实养分的影响。结果表明:土壤中碱解氮、有效磷、速效钾、有机质含量大小依次为0.7M>0.5M>0.3M,这说明在一定范围内,有机肥替代比例越高,土壤养分(碱解氮、有效磷、速效钾、有机质)含量就越高;5个处理试验饱和含水量大小依次为0.7M>0.5M>0.3M,土壤容重大小依次为0.7M<0.5M<0.3M,土壤总孔隙度大小依次为0.7M>0.5M>0.3M,说明在一定范围内,随着有机肥占比的增加,土壤的物理性质依次得到相应改善;土壤中过氧化氢酶、脲酶活性大小顺序皆为0.3M>0.5M>0.7M,说明0.3M处理为土壤酶活性最高且有机肥配比最适处理;0.7M处理中果实氮、磷、钾养分最高,钙、镁中量元素养分差异不显著,说明与有机肥配比关系较小。此结果说明有机肥替代30%无机肥能保持土壤酶活性,有机肥替代70%无机肥不仅能保证果实养分含量,而且能提高土壤肥力。      

Acidulocompost,a food waste compost with thermophilic lactic acid fermentation: its effects on potato production and weed growth

Acidulocomposting recycles food wastes by means of thermophilic lactic acid fermentation. This process can decrease ammonia volatilization and odor emission during processing and produce compost with high nitrogen (N) content. To compare the yield of potatoes (Solanum tuberosum L. ‘Dansyakuimo’) and the suppression of weeds with acidulocompost (AC) and those with conventional composts and inorganic fertilizer (IF), we conducted field experiments in Miyagi Prefecture, northeastern Japan. Potatoes were cultivated in 2008 and 2009 in an Andosol field treated with AC, conventional food waste compost (FWC), poultry manure compost (PMC), cattle manure compost (CMC), IF, or no fertilizer (NF). AC, but not the other treatments, delayed the emergence of potatoes, and suppressed the emergence of weeds, but it did not inhibit potato growth during the late growth stage or yield. Potato N uptake and tuber yield with AC were significantly higher than those with NF and similar to those with FWC, PMC, and IF. The N uptake efficiencies (ratio of difference between N uptake in the treatment and the control to added N) for AC (10.4–12.7% in 2008 and 2009) were similar to those for FWC and PMC (10.2–13.1%), higher than those for CMC (–1.3 to 6.3%), but significantly lower than those for IF (30.2–42.3%). Our findings indicate that AC has an N supply capacity similar to those of FWC and PMC and additionally suppresses the emergence and growth of weeds.     

肥料无机有机配施对稻茬小麦产量与肥料利用率的影响

为了解无机肥与有机肥配施对稻茬小麦产量与肥料利用率的影响,于2016-2017小麦生长季,在湖北省襄阳市通过田间试验,设置不施肥（CK）、传统测土配方施肥（T1）、90%的传统测土配方施肥量+有机肥（T2）和80%的传统测土配方施肥量+有机肥（T3）4个处理,探讨不同施肥模式下小麦产量、分蘖动态、肥料利用效率和经济效益的差异。结果表明,施肥处理的籽粒产量、穗数和穗粒数均显著高于CK,千粒重较高。T2处理的籽粒产量、穗数、穗粒数和千粒重均高于T1和T3处理。施肥处理间群体密度、有效分蘖数和分蘖成穗率均无显著差异。与CK相比,T1、T2和T3处理的有效分蘖数分别提高51.6%、55.9%和53.8%,分蘖成穗率分别降低11.4%、8.8%和14.7%。T3处理的化肥农学利用效率和偏生产力以及N、P、K肥偏生产力均显著高于T2处理,T1处理最低。T1处理的小麦产投比和净收益均高于其他处理,分别为3.9和5 464.5元·hm^-2。综合来看,在本试验条件下,T2处理是相对高产高效的处理。