Effect of different composts on growth and nitrogen composition of Chinese mustard in an acid red soil

Abstract

A pot experiment was conducted to assess the effect of different kinds of composts on the growth and nitrogen (N) composition of Chinese mustard in acid red soil. There were six treatments including a lime‐chemical fertilizer treatment and a control plot of conventional chemical fertilizer. The plants were harvested 37 days after transplanting and the growth and N composition of these plants were measured. The soil was also sampled, and selected chemical properties were determined after harvesting the plants. The results show that different composts affected the growth and soil chemical properties significantly. The pH, nitrate nitrogen (NO₃‐N), ammonium N (NH₄‐N), electrical conductivity (EC), and 1 N ammonium acetate exchangeable potassium (K), calcium (Ca), magnesium (Mg), aluminum (Al), manganese (Mn), and iron (Fe) were all significantly affected by the compost treatment. The growth of plants in the control treatment was significantly lower than that of the compost‐treated and lime‐treated plants, suggesting that the acid Oxisol is unfavorable for the growth of Chinese mustard. Some composts could increase the growth of Chinese mustard. The lime‐treated plants had higher concentrations of chlorophyll a and chlorophyll b than those of the compost‐treated plants. There were no significant differences between treatments in the concentrations of chlorophyll a and chlorophyll b, however, there was a close correlation between the total chlorophyll concentrations and the shoot yield of the plants. The NO₃‐N, soluble reduced N, and insoluble N concentrations in leaf blades and petioles of Chinese mustard varied significantly according to the compost applied. The hog dung compost B could adequately supply nutrients especially N for plant growth and caused little NO₃‐N accumulation in plant tissues.     

EM堆肥对土壤生物影响的研究

长期定点施用EM堆肥试验结果表明:EM有机堆肥能提高土壤细菌、真菌、放线菌数量;相同有机物料投入水平下,EM堆肥处理的微生物总量最高;随着有机物料投入水平的降低,土壤微生物数量下降;施用EM能提高土壤微生物活性,增加微生物的分布密度。施用EM堆肥土壤蚯蚓数量均显著高于其他施肥处理。EM堆肥各处理平均土壤螨虫数量高,但在相同的有机物料投入水平下,差异不显著。在大部分作物生长期,施EM 15t/hm2处理与化肥处理和对照处理土壤生物总量差异显著。     

Cadmium fractions in an acid sandy soil and Cd in soil solution as affected by plant growth

In a previous experiment, plants were able to immobilize or solubilize Cadmium (Cd) in a sandy acid soil enriched with 40 μmol Cd kg^–1, because Cd solution concentration was decreased by maize (Zea mays) and sunflower (Helianthus annuus), and increased by flax (Linum usitatissimum L. ssp. usitatissimum) and spinach (Spinacia oleracea). It is assumed that the equilibrium with Cd fractions in the soil solid phase and the chemical form of Cd in the soil solution were affected. In the present study, the effect of the four plant species mentioned above on Cd binding in soil was investigated by means of a fractionation of soil Cd with a sequential extraction of seven steps. The seven fractions of Cd are operationally defined by the extraction sequence that follows the order of increasing acidity with extractants of different complexing and redox properties. In the unplanted soil, Cd was predominantly present in the exchangeable Fraction I (F. I) and easily mobilizable Fraction II (F. II) (64%). Significant concentrations of Cd were found in F. III (occluded in Mn oxides; 22%) and F. IV (organically bound; 10%). Fractions V (occluded in poorly crystalline Fe oxides), F. VI (occluded in well crystallized Fe oxides), and F. VII (residual fraction) amounted to less than 5% of the total soil Cd concentration. The plants changed the binding of Cd in soil in a different manner. All plants decreased F. I, but F. II was increased by maize and spinach, decreased by flax or remained unaffected by sunflower. Fraction III was not affected by maize and flax, but decreased by sunflower and spinach, and F. IV was not affected by sunflower and spinach, but was increased by maize and flax. These changes of Cd fractions were not related to the changes the plants had caused in total Cd or Cd²⁺ concentration of the soil solution. These results show that plant species differ in how they affect Cd binding to the soil solid phase, but this effect is not related to how they affect Cd in soil solution. The mechanisms by which plants affect the relationship between the soil solid and liquid phase are still unclear.     

Effect of rice plant growth on denitrification in rhizosphere soil

The effect of rice plant growth on the loss of basal nitrogen (N) through denitrification in the rhizosphere of subsurface soil was investigated by the ¹⁵N balance method. Labeled ¹⁵N was applied to the deep soil layer to distinguish between the N losses in the surface and subsurface soils. Denitrification in pots with whole plants (Control) was compared with that in pots with plants cut off at the base of the culm (Pcut) to evaluate the effect of plant growth on denitrification. The upward movement of the applied ¹⁵N from the deep soil was negligible. Thus, the amount of unrecovered ¹⁵N was equal to the amount of N lost through denitrification in the rhizosphere of the subsurface soil (20–150 mm soil depth). In the Control treatment, values of redox potential at 50 and 90 mm soil depths were negative throughout the experimental period. Therefore, it was assumed that the redox potential could not have been the limiting factor for the N loss through denitrification in this experiment. The α-naphthylamine-oxidizing activity of roots decreased drastically after the cutting treatment. The estimated amount of de nitrified ¹⁵N in the rhizosphere of the subsurface soil was significantly higher in the Pcut treatment than in the Control one at 30 and 40 d after transplanting (DAT), while it was comparable in the two treatments at 52 and 64 DAT. Since a greater amount of ¹⁵N loss was found to occur when there was no absorption of ¹⁵N by the plants, the absorption of ¹⁵N by plants may have contributed to the suppression of denitrification. The amount of immobilized ¹⁵N in the Control treatment was larger than that of the Pcut treatment throughout the experiment. N immobilization might have also contributed to the suppression of denitrification in the rhizosphere of the subsurface soil.     

绿化植物废弃物堆肥对城市绿地土壤的改良效果

针对城市中普遍存在的绿地土壤退化和有机废弃物处理处置难的现状,选择典型城市土壤进行绿化植物废弃物堆肥不同用量的绿地现场土壤改良实验.结果表明:绿化植物废弃物堆肥能提高土壤持水能力;降低土壤的酸碱度;增加土壤有机质、总N、总P、有效P、生物量C、N和微生物总量;堆肥对土壤全K的含量总体影响不大,但速效K的含量却成倍增加;说明绿化植物废弃物能改善土壤理化性质,提高土壤肥力,且随着堆肥用量的增加,对土壤的改良作用也越显著;鉴于绿化植物废弃物高C/N,其用量宜控制在13240 kg/hm~2以内.绿化植物废弃物堆肥就地利用即能改良城市退化土壤,又减少城市废弃物量,有利于提高城市生态环境质量.     

不同施肥模式对赤红壤旱地作物产量和土壤肥力的影响

采用长期定位田间试验,研究不同施肥模式对赤红壤旱地花生一甘薯轮作制产量和土壤肥力的影响.5年定位试验表明,平衡施肥平均产量最高,花生和甘薯比常规施肥增产13.1％～13.5％,净增收提高14.0％;氮磷钾对花生和甘薯的增产率逐年提高,但花生和甘薯分别对缺磷和缺钾较敏感.年际间产量变化趋势表明,常规施肥对花生和甘薯产量的变异系数大于平衡施肥;不施肥区和氮磷钾缺素区的产量均呈现逐年下降,但缺氮对花生产量的敏感性大于甘薯,甘薯缺磷或缺钾对产量的敏感性高于花生.平衡施肥的氮磷钾利用率平均分别为40.9％、17.7％和24.2％;缺素区的土壤供肥量比不施肥区提高了近1倍;土壤有机质都有所提高,施用氮肥都使土壤酸度有所增加;不施肥区和氮磷钾缺素区都使相应的土壤速效养分明显下降;常规施肥使土壤有效磷下降22.5％,碱解氮和速效钾则基本维持不变,但平衡施肥使土壤有效磷含量基本不变,碱解氮和速效钾则分别提高26.2％和38.4％.     

Effect of type of compost and application rate on growth and quality of lettuce plant

Abstract

This study intends to assess the effect of compost types and rates on lettuce growth. A pot experiment was conducted at the greenhouse of the College of Agriculture and Veterinary Medicine experimental station, Saudi Arabia. Three types (chicken residues, animal residues, and mixed organic residues) and four rates (1%, 2%, 4%, and 6%) were added to sandy soil. Lettuce seeds were sown in a nursery. After two weeks, each seedling was transplanted to a pot that contained 15?kg of soil. The lettuce plants were irrigated regularly for 60?days, then harvested following dry weight (DW) and chemical analyses. The results showed great variation in the DW, nutrient content, and heavy metals concentrations between the different compost treatments. It noted that DW of lettuce decreased with increasing rates of compost in certain treatments. Moreover, no plant growth occurred in some treatments derived from the mixed organic residue with higher application rates. The nutrient status of lettuce tissues varies greatly among different types of compost. The concentration of heavy metals and microelements present within the lettuce tissues was significantly affected by the types of compost. Copper (Cu), Zinc (Zn), Lead (Pb), Cadmium (Cd), and Nickel (Ni) concentrations in lettuce tissues ranged between 7.4 and 9.6, 81.5 and 104, 23.3 and 28.2, 3.7 and 5.8, and 27 and 30?mg kg^?1, respectively. It revealed that heavy metals concentration increased in lettuce tissues with an increasing application rate of composts. The content of Zn, Pb, Cd, and Ni in lettuce plants were higher and did not meet the requirement set by national standards.     

灌施木醋液对土壤性质和植物生长的影响

本研究以木醋液为研究材料,采用培养试验的方法,研究了灌施不同稀释倍数的木醋液对土性状(pH、 电导率、 土壤结构、 有机碳)和辣椒生长的影响。结果表明,灌施木醋液后土壤pH随灌施量的增大而降低,EC 值随灌施量增大而升高;灌施木醋液（稀释倍数小于5 倍）能够显著提高土壤有机碳的含量,可增加2 mm、 0.25~2 mm 级别土壤团聚体的数量,有利于大团聚体的形成。生物试验表明,稀释 5 倍以下的木醋液对辣椒产生毒害作用,稀释50倍以上的木醋液可以促进辣椒生长,并增加其产量。综合考虑,建议在农田休闲季节灌施木醋液的稀释倍数为35倍左右,在作物生长季节灌施木醋液的稀释倍数为50~250倍。     

Effect of amending materials on growth of radish plant in salinized soil

The critical Na levels in soil which restricted seed germination and growth of radish, and effect of the amending materials on reducing the salinity hazard were determined by performing petri dish and pot experiments. The plants were grown in amended salinized soil in a phytotron for 21 days. Excess accumulation of Na in cells suppressed seed germination and plant growth. The critical Na level in control soil which restricted germination and growth was 12.5mg Na/g soil. At the same salinity level, amending materials promoted seed germination and plant growth mainly by inhibiting the excess flow of Na into the cell through ion holding mechanism. Among the materials used, the commercial manure of 4 months old held greater amount of Na(3.7mg/g) and thus more efficiently reduced the ion damage. Plants grown under such treatment had the highest dry matter yield (28.Gmg/plant), water content was normal(84%), and the ratio for Na in root to Na in plant's shoot was 2.4. As for the case of plant grown in control soil the respective data were 8. 5mg, 54%, and 4.8.     

造纸污泥堆肥对酸性土壤铝污染的影响

通过盆栽试验,研究在砖红壤中施加富含铝盐的造纸污泥堆肥后,土壤－作物体系中的铝毒效应。试验结果表明：盆栽初期,添加造纸污泥堆肥各处理土壤中的总酸溶性铝和总单核铝浓度较CK呈显著上升趋势,并随堆肥用量的增加而增加;随着种植时间推移,各处理（除了CK）总酸溶性铝和总单核铝浓度显著降低,且在盆栽结束时各处理总酸溶性铝浓度均低于原砖红壤中总酸溶性铝浓度;在整个盆栽期间,总单核铝是土壤中活性铝的主要存在形态;添加堆肥的各处理玉米植株的根部和地上部分铝含量均显著小于CK,玉米的生长状况均优于CK,说明在酸性土壤中添加造纸污泥堆肥,能起到很好的肥效作用,且不会对玉米生长形成铝毒效应,其中10%为本试验的最佳配比;另外,土壤理化性质测定结果显示：添加造纸污泥堆肥能有效减缓土壤酸化、增加土壤有机质和有效磷含量,提高土壤质量。     

Effect of soil pH on plant growth and nodulation of cowpea

Abstract

A study was conducted to evaluate the effect of soil pH on rhizobium inoculation, plant growth and nodulation of cowpea (Vigna unguiculata). Both inoculated and non‐inoculated seeds of the cultivar ‘California Blackeye No. 5’ were grown in the greenhouse in plastic pots with growth medium being a Norfolk sandy loam (Fine, loamy siliceous, thermic, Typic Palendult) soil under different pH levels. Both soil pH and rhizobium inoculation significantly affected root length, plant height, nodule and pod number per plant. Within the pH range of 6.6 to 7.6, these growth parameters generally were at their maximum, decreasing above or below this pH range. Non‐inoculated plants produced some nodules, indicating failure of the methyl bromide to totally destroy all residual soil rhizobta before inoculation treatment.

The inoculated plants produced more seeds and the increased number of nodules of treated plants was directly related to increased seed weight. Since nodule number was highest at the approximate pH range of 6.6 to 7.6, this range was considered optimum for nodulation of cowpea by this strain of rhizobium under greenhouse conditions. At pH 7.5 and above, roots tended to be more fibrous and nodules were generally smaller in size.     

植物根系对花岗岩发育的红壤的渗透力和抗蚀力的影响

Distribution of plant roots in a red soil derived from granite was investigated to study the effect of plant roots on intensifying soil penetrability and anti-scouribility by the double-cutting-ring and the undisturbed soil-flume methods, respectively. The plant roots system consisting mostly of fibrils, ＜ 1 mm in diameter, was mainly distributed in the upper surface soil 30 cm in depth. It can remarkably increase the penetrability and anti-scouribility of the red soil derived from granite. When the root density was ＞ 0.35 root cm-2, the intensifying effect of roots on both the penetrability and the anti-scouribility could be described by exponent equations, △Ks = 0.0021RD1.4826 (R2 = 0.9313) and △As = 0.0003RD1.8478 (R2 = 0.9619), where △Ks is the value of intensified soil penetrability, △ As the value of intensified soil anti-scouribility and RD the root density, especially in the top soils within 30 cm in depth where plant roots were concentrated.     

Stabilized municipal sewage sludge addition to improve properties of an acid mine soil for plant growth

Purpose

Degraded soils, such as those encountered in areas of mine activities, need to be ameliorated by liming to correct soil acidity and by addition of organic inputs to improve soil properties and fertility.

Materials and methods

Non-amended mine soil and soil amended with stabilized sewage sludge were incubated for 45 days. Soil physicochemical and biological indicators were periodically measured along incubation and other enzyme activities at the end of incubation. In improved soils, a study of plant development in 250-g pots was carried out with three vegetal species: tomato, rye grass and ahipa. Germination and mortality rates, biomass production and photosynthetic pigments were measured.

Results and discussion

Soil incubation with sewage sludge slightly increased soil pH and led to an enhancement of soil electrical conductivity, organic carbon and dehydrogenase activity, especially for the higher doses (5 and 10%). However soil respiration was more promoted with the 2% dose, pointing to a possible toxic effect of the sludge. At the end of incubation, physicochemical and biological properties were in general enhanced. Biomass production was improved in tomato and rye grass by sewage sludge addition (more at the 2% dose), whilst ahipa growth was not affected by sewage sludge treatments. Tomato mortality reached 73% with high sludge doses (10%).

Conclusions

According to this set of parameters, amendment with sewage sludge of a limed acid mine soil would be considered as a good strategy for soil amelioration in view of plant establishment and development.     

氨基酸菌肥施用量对茶树生长及土壤肥力的影响

为探究不同氨基酸菌肥施用量对茶树生长和土壤肥力含量的影响,以鸿雁12号茶树为研究对象,采用田间微区试验的方法,设置了不施用氨基酸菌肥作对照组(CK)和氨基酸菌肥施用量分别为75 kg·hm^-2(T1)、150 kg·hm^-2(T2)、225 kg·hm^-2(T3)和300 kg·hm^-2(T4)的处理,研究不同氨基酸菌肥施用量对茶树生长、茶叶品质及土壤肥力的影响。结果表明：氨基酸菌肥施用后能显著增加茶叶芽头密度及茶叶产量,提高茶叶中氨基酸含量和土壤中碱解氮含量。试验6个月后与CK相比,T4组的芽头密度显著增加了63.4%,茶叶产量显著增加了71.5%;T1～T4处理茶叶中氨基酸含量分别增加了9.73%、6.41%、7.57%和13.2%,土壤中碱解氮含量分别增加了25.0%、36.0%、46.0%和37.6%。综上,氨基酸菌肥的施用能提高茶叶产量及品质,改善茶园土壤环境质量,为茶园生产的合理施肥及优质高效生产提供数据参考。     

Fortified cassava peel compost amendment for Amaranthus: Influence on plant growth,nutrients uptake and on soil nutrient changes

Nutrient supply through organic sources usually requires fortification for timely and optimum release of plant nutrients to achieve optimum crop performance. A pot experiment was conducted in a screen house to determine the optimum rate of cassava peel compost (CPC) fortification that supports optimum Amaranthus (Amaranthus cruentus L.) plant nutrient contents and residual soil nutrient contents. A compost of cassava peel and poultry manure was applied at 2.5; 5.0 and 7.5 t ha^?1each complemented with either 25 or 50 kg nitrogen (N), using nitrogen, phosphorus and potassium (NPK) 20-10-10 at 2 weeks before sowing Amaranthus. An unfertilized treatment served as control. Seeds were sown in plastic containers with a surface diameter of 24 cm filled with 5 kg soil, with a drain underneath. Seedlings were thinned to 4 plants/pot 2 weeks after planting. Plants were harvested at 5 weeks by ratooning and plant re-growth also harvested after 5 weeks. Soil pH was lower with high rates of 5.0 and 7.5 t ha^?1 CPC while the organic matter content was increased with increased CPC rate. Soil N was reduced but reflected in increased plant shoot and root N, with compost application. Soil P was generally increased but was not reflected in plant contents. Soil K contents were reduced and were reflected in increased plant contents. Application of 2.5 t ha^?1 CPC, fortified with either 25 or 50 kg N ha^?1 gave the optimum Amaranthus shoot nutrient contents with optimum residual soil nutrient contents.     

施肥措施对红壤结构的影响

利用长期定位试验研究红壤开垦利用后不同施肥措施下红壤结构的变化结果表明,红壤开垦利用后,＞1mm机械稳定性大团聚体有所增加,而1mm水稳定性团聚体含量有所下降,但施用有机肥可缓冲1mm大团聚体含量下降的趋势,增加＞0.25mm大团聚体总量.红壤开垦利用后土壤容重变小,土壤孔隙度增加.施用有机肥可使土壤毛管孔隙度增加50%,有效水库容增加64%,而施用化肥仅分别比荒草地红壤增加27%和33%.施用绿肥、稻草或秸秆还田有利于提高土壤的持水性能,而施用化肥对土壤持水性能似无明显改善作用.     

Effects of earthworm casts and compost on soil microbial activity and plant nutrient availability

Vermicomposting differs from conventional composting because the organic material is processed by the digestive systems of worms. The egested casts can be used to improve the fertility and physical characteristics of soil and potting media. In this study, the effects of earthworm casts (EW), conventional compost (CP) and NPK inorganic fertilizer (FT) amendments on N mineralization rates, microbial respiration, and microbial biomass were investigated in a laboratory incubation study. A bioassay with wheat (Triticum aestivium L.) was also conducted to assess the amendment effects on plant growth and nutrient uptake and to validate the nutrient release results from the incubation study. Both microbial respiration and biomass were significantly greater in the CP treatment compared to EW treatment for the initial 35 days of incubation followed by similar respiration rates and biomass to the end of the study at 70 days of incubation. Soil NO₃⁻ increased rapidly in the EW and CP treatments in the initial 30 days of incubation, attaining 290 and 400 mg N kg⁻¹ soil, respectively. Nitrate in the EW treatment then declined to 120 mg N kg⁻¹ soil by day 70, while nitrate in the CP treatment remained high. While ammonium levels decreased in the CP treatment as nitrate level increased with increasing incubation time, a low level of ammonium was maintained in the EW treatment throughout the incubation. The wheat bioassay study included two additional cast treatments (EW-N and EW2) to have treatments with higher levels of N input. Plants grown with CP or FT treatment had a lower shoot biomass and higher shoot N content than in EW-N and EW-2 treatments, and also showed symptoms of salinity stress. Ionic strength and other salinity indicators in the earthworm cast treatments were much lower than in the CP treatment, indicating a lower risk of salinity stress in casts than in compost. All cast and compost amendments significantly increased wheat P and K uptake compared to either the non-amended control or the mineral fertilizer treatment. The results show that casts are an efficient source of plant nutrients and that they are less likely to produce salinity stress in container as compared to compost and synthetic fertilizers.     

不同改良材料对红壤酸度的改良作用及玉米生长的影响

通过盆栽试验分析了4种改良材料(生物炭、炭基肥、猪粪、石灰)及其用量对红壤pH、交换性酸、土壤养分以及玉米生长的影响。共设置10个处理:不添加改良材料的对照(CK),添加1%和3%生物炭(B1、B3),1%和3%炭基肥(BF1、BF3),猪粪替代化学氮肥20%和40%(M20、M40),0.02%和0.04%石灰(L0.02、L0.04),M20+L0.02(M20L0.02)。结果表明,与CK相比,BF3、生物炭、有机肥和石灰处理均能维持红壤pH,而BF1处理显著降低了土壤pH,降幅为0.19个单位;B3、BF1、M40和L0.04处理均显著降低了土壤交换性酸含量。BF1和BF3处理较CK土壤碱解氮含量分别增加了83和305 mg/kg;M40处理土壤有效磷含量显著增加4.1 mg/kg,而M20处理无显著差异;B1、B3和BF3处理较CK土壤速效钾含量分别增加46、138和171 mg/kg。与CK相比,BF3%处理地上部生物量显著降低37%;各改良措施间以B3处理最高,显著高于BF3、M20、L0.02、L0.04和M20L0.02处理。与CK相比,BF3处理显著增加玉米吸氮量,增幅为32%,而其它处理无显著变化。研究表明,4种改良材料均可以改善红壤酸度;综合作物生长和养分平衡,以生物炭作为红壤酸度改良材料,可适当减少钾肥投入,炭基肥则可减少化学氮、钾肥投入,以猪粪为材料则可减少化学磷肥投入。     

4种土壤调理剂改良红壤铝毒害的效果研究

在温室条件下,采用植物盆栽试验,研究4种土壤调理剂不同施用量对酸性红壤铝毒害的缓解效果。结果表明,4种土壤调理剂均显著降低土壤中交换性铝含量及毒害性铝含量,显著提高玉米株高、生物量;各处理土壤中交换性铝含量与玉米株高及生物量之间呈显著相关性。牡蛎壳、白云石、钾长石、麦饭石4种土壤调理剂0.2%的施用量土壤交换性铝分别比对照下降了63.8%、70.5%、53.0%、12.3%;0.4%的施用量土壤交换性铝分别比对照下降了90.5%、92.0%、80.5%、23.4%。土壤中交换性铝、毒害性铝的含量随着4种土壤调理剂的施用量增加而降低,土壤中毒害性铝含量由低到高依次为白云石、牡蛎壳、钾长石、麦饭石。