The influence of variation in soil copper on the yield and nutrition of cauliflower grown in organic soil microplots

Abstract

Cauliflower (Brassica oleracea Botrytis cv. Snow Crown) was grown in field microplots of an organic soil containing residual fertilizer Cu varying from 81 to 1063 ppm (w/w) as a result of three levels of Cu applications made in the previous two seasons. The variation in soil‐Cu was found to have no significant influence on the yield, nutrition or copper status of the crop.     

The effect of residual copper levels on the nutrition and yield of oats grown in microplots on three organic soils

Abstract

Oats (Avena sativa L. cv. Garry) were grown in microplots of three organic soils at site A (peat), site B (muck) and site C (mucky peat) in the summer of 1983. The soil surface (0 to 20 cm) varied in total Cu from 13 to 1659, 135 to 1745, and 81 to 1063 μg/g at sites A, B and C, respectively, due to applications of CuSO₄.5H₂O made at three rates in 1978, at sites A and B, and in 1979 at site C. Neither the rates of Cu application nor total soil Cu influenced yields. High levels of residual Cu increased the levels of Cu in straw at sites A and B, and in grain at site C. However, even the highest levels of Cu in straw and grains, were below the 20 μg/g which is often considered to be the threshold of Cu phytotoxicity. Data on the levels of other nutrients (P, K, Ca, Mg, Fe, Mn, Zn, B, Mo and S) in the tops and roots of oats generally revealed no significantly adverse effects of the Cu applications or total accumulated Cu in the three soils.     

Bacteriological studies on the mineralization of organic nitrogen in paddy soils

In this report we studied the effects of mechanical grinding of paddy soils on nitrogen mineralization and bacterial number when soils were incubated under a submerged condition after grinding.

Nitrogen mineralization was increased by grinding soil samples as compared with those without grinding. The value of (Nd-Nu)/Nu, where Nd is the amount of ammonia-nitrogen formed by incubation of disrupted samples and Nu those of the undisrupted soils, was in good correlation with clay/humus ratio.

Although significant difference was not observed between the number of aerobic bacteria with undisrupted and disrupted soil samples, higher anaerobic bacterial numbers were found with disrupted than with undisrupted ones.

A significant correlation was also obtained between the amounts of nitrogen mineralization increased by the grinding of soil and the numbers of anaerobic bacteria.     

Nutrient concentration and yield variation within southern soybean germplasm grown on acid Norfolk soil

Abstract

Seventy‐one soybean genotypes were grown in the field on an acid Norfolk loamy sand to evaluate growth, seed yield, and nutrient concentrations in aerial plant fractions. The pH values in the Ap, A2, and B horizons were 4.6, 4.4, and 4.4, respectively. Cation exchange capacities (CEC) were 2.1, 0.9, and 2.8 me/100 g with an Al saturation of 34, 49, and 40%, respectively. Very few visual toxicity or deficiency symptoms were found among the genotypes. Analyses of aerial plant fractions collected when the genotypes were in bloom or early pod fill showed some significant differences, but In general P, K, Ca, and Mg concentrations were adequate, while Al, Fe, Mn, and Zn concentrations were very high. Average yields of genotypes in maturity groups IV, V, VI, VII, and VIII were 2.7, 2.7, 2.6, 2.4, and 2.2 t/ha, respectively. There were significant differences in seed yield among genotypes in maturity groups IV and VIII, but differences among genotypes in the other maturity groups were nonsignificant. Correlations between yield and nutrient concentration showed some significant relationships, but in general, this technique did not differentiate genotypes according to their tolerance to acid soil conditions.     

The effect of gypsum on copper nutrition of wheat grown in marginally deficient soil

This study reports an interaction between copper nutrition of wheat and application of gypsum. A pot experiment and two years of field trials on a sandy duplex soil in the southern Wimmera, Australia showed that the efficacy of copper applied to the soil is increased by the application of gypsum. Severity of attack by the fungus Gaeumannomyces graminis (take‐all) was greatly reduced in the pot experiment by the addition of either copper or gypsum to the soil. In the second year of the field experiments, copper deficiency occurred only on areas which had been ripped. These results are discussed in relation to factors controlling the availability of copper in soil.     

Effect of organic and mineral fertilizers on soil respiration and enzyme activities of two Mediterranean horticultural soils

The effects of municipal food waste compost addition and mineral fertilization on selected soil microbiological activities were investigated during 3 years of reiterated treatments on two Mediterranean agricultural soils with different organic carbon content. Compost at 15, 30 and 45 t ha⁻¹ (dry matter), mineral (NPK) fertilizers and combined fertilizers with 15 t ha⁻¹ of compost plus two reduced doses of mineral N were applied to both soils. At both sites, organic amendment increased soil respiration, fluorescein diacetate hydrolysis, phosphatase and arylsulphatase activities. The differences in soil microbial activities among treatments, found after 3 years of repeated treatments, were attributable to the variations of soil organic C content and to the impact of soil tillage. Our results show that, in Mediterranean intensively cultivated agroecosystems, annual organic amendments improve the microbial activity of soil and produce cumulative effects, suggesting the usefulness of repeated high-rate compost applications.     

The influence of soil compaction and the removal of organic matter on two native earthworms and soil properties in an oak-hickory forest

 Earthworms may alter the physical, chemical, and biological properties of a forest soil ecosystem. Any physical manipulation of the soil ecosystem may, in turn, affect the activities and ecology of earthworms. The effects of removing organic matter (logs and forest litter) and severely compacting the soil on native earthworm species were measured in a central USA hardwood region (oak-hickory) forest in the Missouri Ozarks (USA). Soils in this region are characterized by a cherty residuum that is primarily of the Clarksville series (Loamy-skeletal, mixed, mesic Typic Paledults). Earthworms were collected from 0–15 cm depth each spring and fall for 2 years by handsorting, and densities were determined on a per meter square basis. Two native earthworm species, Diplocardia ornata and Diplocardia smithii, were dominant on this site. Organic matter removal decreased the average individual biomass of both species. However, both species responded differently to soil compaction. Soil compaction affected D. ornata adversely and D. smithii favorably. This suggested that the degree of soil compaction was not as restrictive with respect to D. smithii (2 mm diameter) as to D. ornata (5 mm diameter). Moreover, the apparently improved soil environmental conditions resulting from the remaining organic matter in compacted soil enhanced the population and growth of D. smithii. Sampling position on the landscape affected D. ornata but not D. smithii. Soil microbial biomass C and soil microbial biomass N were decreased under soil compaction when the organic matter was removed. Other factors influencing the ecology and activity of these two species will require further study. Received: 6 January 1999     

不同有机肥源对土壤微生物生物量及花生产量的影响

通过盆栽试验,采用平板计数法和DGGE分析法,研究施用化肥与不同来源的有机肥对土壤微生物生物量及花生产量的影响.结果表明,施肥均显著提高了花生的经济产量与生物产量,其中以施用麸酸有机复混肥处理最高;土壤中细菌、真菌、放线菌总量以施用鸡粪处理最高,其他处理差别不大;土壤微生物总DNA提取、PCR扩增及其产物DGGE分析表明,施用各品种有机肥较不施肥与施用化肥促进了土壤某些微生物量的提高,而施用不同有机肥品种促使不同种类微生物量的提高.故不同有机肥源对土壤微生物生物量乃至其多样性特征均产生影响.     

黄土高原区长期施用有机肥对土壤肥力及小麦产量的影响

黄土高原区长期定位试验麦秸、玉米秸、绿肥、厩肥及化肥等培肥物质对土壤养分及小麦产量的影响结果表明,长期施用有机肥可明显提高土壤有机质、全量养分和速效养分含量,提高土壤酶活性,改善土壤有机无机复合体、土壤水分、物理形状和土壤团聚度,提高调节土壤水、肥、气、热等能力,其中秸秆增产效果最显著。     

The influence of tillage systems on soil organic matter and soil hydrophobicity

Management practices including various tillage systems influence quantity and composition of soil organic matter (SOM). Parameters for evaluating both the SOM quantity (organic C [C_ox], total N [N_t]) and quality (microbial biomass C, hydrophobic and hydrophilic organic components) were determined in soil samples, taken from two soil depths (0–0.1 m and 0.1–0.3 m) in a field experiment in the period 2001–2007, with different tillage systems. The experiment, founded in 1995 in Prague-Ruzyně, includes conventional soil tillage (CT) plus some selected methods of conservation tillage: (a) no tillage (NT), (b) no tillage + mulch (NTM), and (c) minimum tillage with pre-crop residues incorporated (MTS). C_ox and microbial biomass C contents increased significantly with conservation tillage as compared to CT in 0–0.1 m layer, non-significant increase was found in 0.1–0.3 m layer. N_t increased non-significantly in both layers. Along with the depth of sampling, the content of the characterized parameters decreased in all variants; but the decrease in the conventionally tilled variant was, for the most part, lower than in the conservation tillage. The functional hydrophobic and hydrophilic groups of soil organic matter were identified by Fourier transform infrared (FTIR) spectroscopy, and the hydrophobic/hydrophilic group intensities ratio was calculated as the parameter of soil hydrophobicity. A higher soil hydrophobicity existed in all three conservation tillage treatments compared to CT due to the significantly higher content of hydrophobic organic components. C_ox correlated significantly with microbial biomass C, N_t, hydrophobic components, and soil hydrophobicity (R = 0.552–0.654; P < 0.05). Hydrophilic components did not correlate with other soil characteristics, with the exception of hydrophobic components. These data show that shifting from CT to the conservation tillage systems increased the content of SOM in top soil layer in relatively short time, improved the SOM quality and increased soil hydrophobicity in the condition of experiment.     

Effect of organic manure on organic phosphorus fractions in two paddy soils

We investigated the transformation of the organic P fractions from organic manure in two paddy soils (Ultisol, Entisol) and the influence of organic manure or cellulose on organic P under anaerobic conditions. The results obtained from the P fractionation experiment indicated that during the incubation labile and moderately labile organic P fractions increased in the Ultisol and decreased in the Entisol, which might be related to the difference in the organic matter content of both soils. Immediately after the application of organic manure, a large part of labile and moderately labile organic P supplied with the manure was transformed into moderately resistant organic P, possibly Ca- or Mg-inositol P were transformed into Fe-inositol P. During anaerobic incubation, the labile forms of organic P in the soils treated with organic manure were increased along with the incubation period in the first 4 weeks. The change in the moderately labile fraction was dramatic. It increased sharply in the first 2 weeks, then decreased, which was more pronounced in the soils treated with pig faeces. The moderately resistant fraction decreased during the whole incubation period. This indicated that under anaerobic conditions, the moderately resistant fraction can be transformed into labile and moderately labile organic P fractions, perhaps as Fe³⁺-inositol P is reduced to Fe⁺²-inositol P. Cellulose as an organic substrate had an increasing effect on organic P, especially when it was combined with inorganic P. Therefore, it is suggested that the application of inorganic P fertilizer combined with organic manure may be an effective way of protecting inorganic P against intensive sorption in soils.     

有机肥施用模式对蔬菜产量、土壤化学性质及微生物的影响

在广州市蔬菜集约化种植区连续进行了6茬菜心试验,探讨有机肥施用模式[施无机肥(CK)、无机肥配施国产生物有机肥(BM)、无机肥配施腐殖酸(HA)、无机肥配合淋施复合芽孢杆菌剂(BSP)、无机肥配施腐殖酸并淋施复合芽孢杆菌剂(HA+BSP)、无机肥配施水沤腐熟鸡粪并淋施复合芽孢杆菌剂(CM+BSP)、无机肥配施复合芽孢杆菌剂堆沤腐熟鸡粪(BSPCM)]对蔬菜产量、土壤化学性质及微生物的影响。结果表明,不同茬别菜心产量差别较大。连续6茬试验中,CM+BSP处理菜心产量均为最高且显著高于CK处理,BSPCM处理菜心产量仅次于CM+BSP处理。BM、CM+BSP、BSPCM处理能提高土壤pH,降低连作土壤的酸化风险。随着种植茬数的增加,CM+BSP处理土壤细菌、真菌和微生物总数持续增加,显著高于原始土壤和其他施肥处理,BSPCM处理次之。CK处理土壤中细菌、真菌及微生物总量均比原始土壤下降。在连作菜地蔬菜生产中,在施用无机肥基础上配施适量水沤腐熟鸡粪,并在蔬菜生长过程中淋施复合芽孢杆菌剂,不但可提高蔬菜产量,而且具有培肥、活化和改良土壤生物质量的作用,有利于减轻蔬菜连作障碍,实现集约化蔬菜种植的可持续发展。     

Fractionation of soil phosphorus in organic amended farms located on savanna sandy soils of Venezuelan Amazonian

In Venezuelan Amazonian, some producers have established small agroforestry systems of production on sandy savanna soils by a long-term addition (more than 25 years) of animal manures at a low dressing (2 Mg ha⁻¹) as fertilizer input. As a result of the organic fertilizers regime, the original savanna soil has been changed in terms of soil quality parameters. The main objective of the study was to investigate using sequential fractionation of soil P the impact of organic manures on the amount and partitioning of bioavailable P in soils of the Amazonas. Fractionation was carried out on Typic Ustipsamments amended with three different organic manure sources for extended periods. In general, after fertilization, all Pi and Po fractions increased significantly. The increase was striking in the resin-Pi and HCl-Pi, and among the organic P fractions, the changes were highest for the NaOH-Po sonicated and non-sonicated fractions. The total P increment was more relevant when soils were amended with chicken manure (1,194 mg Pt kg⁻¹) and less relevant for the farm soil treated with compost (500 mg Pt kg⁻¹), where the soil amended with cattle waste presented an intermediate value in total soil P (851 mg Pt kg⁻¹). The importance of this field study was to assess the sustainability of long-term established organic management characterized by the low inputs, and this information is poor in the Amazonas.     

铜耐性优势植物根际土壤铜抗性菌株的筛选及其对铜的促溶作用

从铜矿废弃地重金属耐性优势植物根际土壤中分离筛选到两株抗高浓度Cu的细菌菌株HQN2和JYC17.对菌株HQN2和JYC17溶解难溶性Cu的作用进行了研究.结果表明:菌株HQN2和JYC17具有明显的溶解碳酸铜的能力,与接灭活菌对照相比,菌株HQN2和JYC17分别使培养液中水溶性Cu含量增加306%和136%,培养液的pH由初始的7.00分别降低到4.08和4.46.另外,Cu能促进供试菌株有机酸(葡萄糖酸、苹果酸和乙酸等)的合成.菌株HQN2和JYC17对土壤中难溶性Cu亦有明显的促溶作用.与接灭活菌对照相比,菌株JYC17和HQN2分别使土壤中交换态Cu含量增加110%和270%.经生理生化特征分析及16S rDNA序列分析,菌株HQN2和JYC17分别被鉴定为节杆菌属(Arthrobacter sp.)和微杆菌属(Microbacterium sp.).     

Fertigation of humic substances improves yield and quality of broccoli and nutrient retention in a sandy soil

There is lack of information available concerning the effect of humic substances (HS) applied via fertigation on plant growth in sandy soils. Therefore, a field experiment was carried out at El‐Saff district (20 km southwest of Cairo), Egypt, to investigate the role of HS fertigation on water retention of a sandy soil, yield and quality of broccoli (Broccoli oleracea L.) as well as on soil nutrient concentration retained after harvest. The experiment consisted of six fertigation treatments (50%, 75%, and 100% of the recommended NPK‐fertilizer rate for broccoli combined with and without HS application at 120 L ha^–1) in a complete randomized block design with three replicates. Humic substances affected spatial water distribution and improved water retention in the root zone. Furthermore, application of HS increased total marketable yield and head diameter of broccoli as well as quality parameters (i.e., total soluble solids, protein, and vitamin C). Higher nutrient concentrations were found in the broccoli heads and concentrations of plant‐available nutrients in soil after harvesting were also higher, indicating an improvement in soil fertility. In conclusion, HS fertigation can be judged as an interesting option to improve soil water and nutrient status leading to better plant growth.     

The impact of a low humus level in arable soils on microbial properties, soil organic matter quality and crop yield

 In arable soils in Schleswig-Holstein (Northwest Germany) nearly 30% of the total organic C (TOC) stored in former times in the soil has been mineralized in the last 20 years. Microbial biomass, enzyme activities and the soil organic matter (SOM) composition were investigated in order to elucidate if a low TOC level affects microbial parameters, SOM quality and crop yield. Microbial biomass C (C_mic) and enzyme activities decreased in soils with a low TOC level compared to soils with a typical TOC level. The decrease in the C_mic/TOC ratio suggested low-level, steady-state microbial activity. The SOM quality changed with respect to an enrichment of initial litter compounds in the top soil layers with a low TOC level. Recent management of the soils had not maintained a desirable level of humic compounds. However, we found no significant decrease in crop yield. We suggest that microbial biomass and dehydrogenase and alkaline phosphatase activities are not necessarily indicators of soil fertility in soils with a high fertilization level without forage production and manure application. Received: 12 December 1997     

Barley yield and soil microbial and enzyme activities as affected by contamination of two soils with lead, zinc or copper

The effects of increasing rates of Pb, Zn and Cu on extractable heavy metal levels, barley yields, basal respiration and the activities of catalase, urease, invertase and acid phosphatase were investigated in two soils in a 2-year greenhouse experiment. In the first year, barley yields were decreased by increasing additions of Pb, Zn and Cu. In the second year, increased yields were recorded at lower rates of addition of all three metals in both the chestnut and chernozem soils. Yield depressions were most marked for added Cu and least marked for Pb but, in contrast, accumulation of heavy metals in grain, in excess of recommended limits, was most pronounced for Pb and did not occur for Cu. Increasing rates of all three metals caused a decrease in basal respiration; the degree of inhibition was generally greater in the second than in the first year. After 1 year of incubation, increasing rates of addition of metals reduced all tested enzyme activities. However, after 2 years, the pattern of response was more complex, with increases in enzyme activities being noted at lower rates of addition of all three metals. In general, invertase and urease activities were more markedly inhibited by heavy metal contamination than those of catalase and phosphatase. Ammonium acetate-extractable heavy metal concentrations in soils were less after 2 years than 1 years reaction time due to their transformation into less labile forms. Significant negative correlations between grain yield, basal respiration and enzyme activities were observed in both years.     

温度与土壤水分对有机碳分解速率的影响

试验研究温度与土壤水分对有机碳分解速率的影响,结果表明:相同水分条件下,培育初期(1～20d)各处理CO2排放速率较高,相对值表现为35℃处理>25℃处理>15℃处理>5℃处理;随培育时间延长(>20d),CO2排放速率渐趋平稳。相同温度条件下,30%～90%田间持水量时培育初期(1～20d)各处理CO2排放速率初始值较高,之后降低,当趋于某一定值时,相对值大小随土壤水分含量增加而增加。相同温度与土壤水分条件下,CO2排放速率相对值大小随土壤有机碳含量增加而增加。     

Erosional impact on organic matter content and productivity of selected Iowa soils

From 1983 to 1989 an erosion-productivity study was conducted in Iowa. The primary objective of this project was to determine the effects of accelerated erosion and its interactions with other variables on soil productivity, as measured by corn yields of loess and till-derived soils in Iowa. Multiple regression techniques were used to relate corn yields to erosion and selected soil, climatic, and weather variables. Organic matter content of the soils was significantly correlated with erosion phase. Yields of till-derived soils decreased more with increasing degree of erosion than loess-derived soils. The conclusions are based on data collected at 569 sites located in 44 Iowa counties.