首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 156 毫秒
1.
Dairy manure (DM) rates of [0 (DM0), 30 (DM30)), 60 (DM60) Mg ha?1] and three nitrogen (N) rates [0 (N0), 125 (N125), 250 (N250) kg ha?1] were tested in a sandy clay loam, to evaluate their effects on growth and yield of wheat crop (Triticum aestivum L.), residual nitrate nitrogen (NO3-N) and phosphorus (P) concentrations in the surface soil, and selected soil physical measurements [saturated hydraulic conductivity (Ksat), and bulk density (BD)]. Increasing N and DM rates gave higher wheat yields, increased concentrations of residual NO3-N and P in the surface soil and improved Ksat and BD. Highest grain yield of 3.8 Mg ha?1 (70.3% more than the control) was observed in DM60 × N250 treatment. Residual accumulation of N-NO3 and P in the surface soil at high N and/or DM application rates suggests the need to carefully manage N and DM inputs on farm fields to avoid environmental contamination.  相似文献   

2.
To evaluate the benefits of application of biochar to coastal saline soil for climate change mitigation, the effects on soil organic carbon (SOC), greenhouse gases (GHGs) and crop yields were investigated. Biochar was applied at 16 t ha?1 to study its effects on crop growth (Experiment I). The effects of biochar (0, 3.2, 16 and 32 t ha?1) and corn stalk (7.8 t ha?1) on SOC and GHGs were studied using 13C stable isotope technology and a static chamber method, respectively (Experiment II). Biochar increased grain mass per plant of the wheat by 27.7% and increased SOC without influencing non‐biochar SOC. On average, 92.3% of the biochar carbon and 16.8% of corn‐stalk carbon were sequestered into the soil within 1 year. The cumulative emissions of CO2, CH4 and N2O were not affected significantly by biochar but cornstalk application increased N2O emissions by 17.5%. The global warming mitigation potential of the biochar treatments (?3.84 to ?3.17 t CO2‐eq. ha?1 t?1 C) was greater than that of the corn stalk treatment (?0.11 t CO2‐eq ha?1 t?1 C). These results suggest that biochar application improves saline soil productivity and soil carbon sequestration without increasing GHG emissions.  相似文献   

3.
A laboratory column experiment was conducted to investigate the effects of 400°C biochar at application rate of 15 g kg?1 (21.9 t ha?1) with different particle sizes (<0.5 mm (S1), 0.5–1 mm (S2) and 1–2 mm (S3)) and application depths (0–2 cm depth (D0), 4–6 cm depth (D5) and 8–10 cm depth (D10)) on hydro-physical properties of sandy loam soil. The results indicated that applying biochar decreased the waterfront and saturated hydraulic conductivity of sandy loam soil. The cumulative evaporation was the highest and amounted to 40.9 mm in the non-treated soil, but it recorded the lowest amount of 32.2–35.5 mm in the biochar-treated soil. Applying biochar caused significant increases in the amount of conserved and retained water with the highest amount of water conserved in soil treated with S2 biochar at D5. Moreover, the cumulative water infiltration through the soil was significantly reduced by S1 and S2 biochars at D0. The values of saturated hydraulic conductivity for biochar treatments were significantly lower than those for the control, with the lowest values for S1 at D0 and D5. These results suggest positive improvement for the hydro-properties of coarse-textured soils following biochar addition, especially with finer particles of biochar.  相似文献   

4.
ABSTRACT

Field experiments were conducted during the 2017 and 2018 cropping seasons, to evaluate the effects of biochar (B) and poultry manure (PM) on soil physical and chemical properties, leaf nutrient concentrations, growth, mineral composition and corm and cormel yield of cocoyam. The experiment each year consisted of 4 × 2 factorial combinations of B (0, 10, 20 and 30 t ha?1) and PM (0 and 7.5 t ha?1). Results of the study indicated that in both years, the application of B and PM alone, and in combination, improved soil physical and chemical properties, leaf nutrient concentrations, growth, mineral composition and corm and cormel yield of cocoyam. There was a significant interaction effect of B and PM (B x PM) which was adduced to the ability of the B to increase PM-use efficiency and promote better use of the nutrients in the PM. It was found that combination of 30 t ha?1 B and 7.5 t ha?1 PM (B30+ PM7.5) gave the highest corm and cormel yield of cocoyam compared with other treatments. The combination of 30 t ha?1 B and 7.5 t ha?1 PM (B30+ PM7.5) exhibited the highest impact and is therefore recommended for soil sustainability and cocoyam productivity on sandy soil.  相似文献   

5.
A greenhouse experiment was conducted in the Department of Soil Science and Agricultural Chemistry, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi (U.P.), India, during kharif 2013 to find out the effect of biochar and sewage sludge (SS) on growth, yield, and micronutrient uptake in rice crop. Nine treatments were employed using six different doses of biochar (2.5, 5.0, 7.5 10, 15, and 20 t ha?1) amended with a fixed dose of SS (30 t ha?1) and 50% recommended dose of nitrogen (50% RDN), i.e., 60 kg ha?1. Other three treatments were absolute control (no fertilizers), 100% recommended dose of fertilizers (100% RDF) which was 120:60:60 kg ha?1 as nitrogen (N): phosphorus pentoxide (P2O5):dipotassium oxide (K2O), and 30 t ha?1SS + 50% RDN. Experimental results showed a significant increase in yield of rice crop with increasing levels of biochar along with SS. Application of biochar at 20 t ha?1 along with 30 t ha?1SS increased grain yield to the extent of 2.5 times over absolute control (no fertilizers) and 8.5% over control (100% RDF). The uptake of iron (Fe), copper (Cu), zinc (Zn), and manganese (Mn) (micronutrients) increased significantly with graded doses of biochar application from 2.5 to 20 t ha?1 in the soil. The maximum micronutrient uptake and grain yield of rice were found in T9 where 30 t ha?1SS along with 20 t ha?1 biochar was applied with only 50% RDN. The maximum availability of micronutrients in soil was found with 30 t ha?1 of SS + 50% RDN (T3) followed by conjoint application of 20 t ha?1 of biochar and 30 t ha?1 SS + 50% RDN (T9).  相似文献   

6.
Biochar application can reduce global warming via carbon (C) sequestration in soils. However, there are few studies investigating its effects on greenhouse gases in rice (Oryza sativa L.) paddy fields throughout the year. In this study, a year-round field experiment was performed in rice paddy fields to investigate the effects of biochar application on methane (CH4) and nitrous oxide (N2O) emissions and C budget. The study was conducted on three rice paddy fields in Ehime prefecture, Japan, for 2 years. Control (Co) and biochar (B) treatments, in which 2-cm size bamboo biochar (2 Mg ha?1) was applied, were set up in the first year. CH4 and N2O emissions and heterotrophic respiration (Rh) were measured using a closed-chamber method. In the fallow season, the mean N2O emission during the experimental period was significantly lower in B (67 g N ha?1) than Co (147 g N ha?1). However, the mean CH4 emission was slightly higher in B (2.3 kg C ha?1) than Co (1.2 kg C ha?1) in fallow season. The water-filled pore space increased more during the fallow season in B than Co. In B, soil was reduced more than in Co due to increasing soil moisture, which decreased N2O and increased CH4 emissions in the fallow season. In the rice-growing season, the mean N2O emission tended to be lower in B (?104 g N ha?1) than Co (?13 g N ha?1), while mean CH4 emission was similar between B (183 kg C ha?1) and Co (173 kg C ha?1). Due to the C release from applied biochar and soil organic C in the first year, Rh in B was higher than that in Co. The net greenhouse gas emission for 2 years considering biochar C, plant residue C, CH4 and N2O emissions, and Rh was lower in B (5.53 Mg CO2eq ha?1) than Co (11.1 Mg CO2eq ha?1). Biochar application worked for C accumulation, increasing plant residue C input, and mitigating N2O emission by improving soil environmental conditions. This suggests that bamboo biochar application in paddy fields could aid in mitigating global warming.  相似文献   

7.
为探究不同生物炭混掺量对微咸水蒸发特性的影响,采用离心机试验和室内土柱模拟试验,设置3个生物炭质量添加比例(B0、B2、B4)和4个微咸水矿化度(W0、W1、W3、W5),分析不同处理对微咸水蒸发下的土壤水分特征曲线、孔隙分布、累积蒸发量、盐分运移、土壤温度日变幅的影响,并应用蒸发模型进行拟合分析。结果表明:生物炭和微咸水联合应用下能提高土壤持水能力,增加土壤中的较大孔隙和较小孔隙的比例;土壤累积蒸发量随着生物炭混掺量的增加先减少后增加,生物炭混掺量为2%时可以更好地抑制微咸水蒸发;Rose蒸发模型可以较好地拟合微咸水蒸发;土壤中混掺生物炭可以降低盐分表聚,使其在土壤中均匀分布;混掺生物炭可以有效降低土壤温度日变幅;相同生物炭施用量下,矿化度为3 g/L的微咸水,可以降低0—10 cm土层土壤平均温度,提高10—50 cm土层土壤平均温度。综合考虑各项指标,处理B2W3的生物炭和微咸水更适宜农田施用,为西北干旱地区更好地利用微咸水灌溉提供理论依据。  相似文献   

8.
ABSTRACT

The aim of this study was to examine the effects of soil amendments to sandy loam and soil physical indices, mainly soil aggregates, soil retention curve, and pore size distribution. Date palm waste biochar at rates 2% (B1), 4% (B2), 6% (B3), and 8% (B4) and sorbent adsorption polymer (SAP) at rates 0.2% (P1), 0.4% (P2), 0.6% (P3), and 0.8% (P4) (w/w). In addition, the combination of both as B1:P1, B2:P2, B3:P3, and B4:P4, were added to the soil as amelioration materials. The results revealed that on the average, soil water content increased by 7.3%, 3.3%, and 15.0% with the addition of biochar, polymer, and the combination, respectively. The location parameters dmode, dmedian, and dmean decreased by 6.4%, 8.8%, and 10.6% for the biochar, and increased by 2.3%, 4.6%, and 3.4% for the polymer treatments, decreased by 4.8%, 4.4%, and 4.2% for the combination treatments, respectively. Shape parameters such as standard deviation (SD), (spread) skewness (asymmetry), and kurtosis (peakedness) were 2.2, – 0.27, and 1.6 for the biochar treatments, 2.17, – 0.27, and 1.6 for the polymer treatments, and 2.17, – 0.23, and 1.6, for the combination treatments, respectively. The aggregate stability (SA) of soils of size 0.25 and 0.13 mm increased by 50.8% and 50% with the application of biochar (B2 = 4%) and polymer (P2 = 0.4%) B2:P2 and polymer (P4 = 0.8%) P4 treatments, respectively. This study recommends using combination of biochar with polymer treatments on sandy loam soil in arid area due to its strong hydro-physical properties.  相似文献   

9.
Abstract

This study was designed to investigate the effect of biochar on maize production and nutrient retention with recommended full and half dose of nitrogen (N) and phosphorus (P) nutrition in loamy soil. In the first study, maize was grown in pots with four levels of biochar (0, 2, 4, and 6?t?ha?1) under two levels of NP fertilizer, viz. recommended (200–150?kg?NP?ha?1) and it’s half (100–75?kg?NP?ha?1) dose. The prominent improvement in plant roots traits, leaf area, plant growth, morphological and yield-related parameters were observed with addition of biochar at 2 and 4?t?ha?1; while, plant height, number of grains per cob, grains and biological yield decreased with biochar addition 6?t?ha?1 along with full dose of NP nutrition. In subsequent field studies, two levels of biochar along with control (0, 2, 4?t?ha?1) were investigated. The more improvement in root growth, leaf area and crop growth was observed when biochar was applied at 2?t?ha?1 with full NP nutrition. Biochar application at 2?t?ha?1 with full NP nutrition produced the highest grain yield (6.64?t?ha?1); however, biochar addition (2?t?ha?1) with half NP nutrition resulted in better grain yield than full dose of NP to enhance maize production as compared with full dose of NP without biochar. Therefore, biochar addition (2?t?ha?1) with half-recommended dose of NP prominently improved the maize productivity in loamy soil and serve as better in replacement of full dose of NP fertilizer.  相似文献   

10.
Intensive vegetable crop systems are rapidly developing, with consequences for greenhouse gas (GHGs) emissions, nitrogen leaching and soil carbon. We undertook a field trial to explore the effect of biochar application (0, 10, 20 and 40 t ha−1) on these factors in lettuce, water spinach and ice plant rotation. Our results show that the 20 and 40 t ha−1 soil treatments resulted in the SOC content being 26.3% and 29.8% higher than the control (0 t ha−1), respectively, with significant differences among all treatments (p < .05). Biochar application caused N2O emissions to decrease during the lettuce and water spinach seasons, by 1.5%–33.6% and 12.4%–40.5%, respectively, compared the control, with the 20 t ha−1 application rate resulting in the lowest N2O emissions. Biochar also decreased the dissolved nitrogen (DN) concentration in leachate by 9.8%–36.2%, following a 7.3%–19.9% reduction in dissolved nitrogen in the soil. Similarly, biochar decreased the nitrate (NO3−) concentrations in leachate by 3.9%–30.2%, following a 3.8%–16.7% reduction in the soil nitrate level. Overall, straw biochar applied at rate of 20 t ha−1 produced the lowest N2O emissions and N leaching, while, increasing soil carbon.  相似文献   

11.
Reducing ammonia (NH3) volatilization is a practical way to increase nitrogen (N) fertilizer use efficiency (NUE). In this field study, soil was amended once with either cotton (Gossypium hirsutum L.) straw (6 t ha?1) or its biochar (3.7 t ha?1) unfertilized (0 kg N ha?1) or fertilized (450 kg N ha?1), and then soil inorganic N concentration and distribution, NH3 volatilization, cotton yield and NUE were measured during the next two growing seasons. In unfertilized plots, NH3 volatilization losses in the straw-amended and biochar-amended treatments were 38–40% and 42–46%, respectively, less than that in control (i.e., unamended soil) during the two growing seasons. In the fertilized plots, NH3 volatilization losses in the straw-amended and biochar-amended treatments were 30–39% and 43–54%, respectively, less than that in the control. Straw amendment increased inorganic N concentrations, cotton yield, cotton N uptake and NUE during the first cropping season after application, but not during the second. In contrast, biochar increased cotton N uptake and NUE during both the first and the second cropping seasons after application. Furthermore, the effects of biochar on cotton N uptake and NUE were greater in the second year than in the first year. These results indicate that cotton straw and cotton straw biochar can both reduce NH3 volatilization and also increase cotton yield, N uptake and NUE. In addition, the positive effects of one application of cotton straw biochar were more long-lasting than those of cotton straw.  相似文献   

12.
Coconut-based farming systems are the tradition of tropical and subtropical regions. But, using patchouli [Pogostemon cablin (Blanco)] as an intercrop under coconut is of comparatively recent adoption and no information is absolutely available on the possibility of improving the quality of patchouli through better nutrient supply. A field experiment was, therefore, carried out using different sources of organic manures (M0–control, M1–FYM farmyard manure 20 tonnes ha?1, M2–pig manure 10 tonnes ha?1 and M3–vermicompost 5 tonnes ha?1) versus inorganic fertilizers (No–control, N1 - 60 kg ha?1, N2–80 kg ha?1, and N3–100 kg ha?1) within the interspaces of the coconut plantation on soil taxonomically classified as Orchic Hapludalf under humid tropics of northeast India. Application of treatment M3 alone produced maximum biomass of leaves (11.24 tonnes ha?1) followed by M2 (10.82 tonnes ha?1), and M1 (9.54 tonnes ha?1), all of which were significantly (P < 0.05) superior over M0 (7.54 tonnes ha?1). Among the various levels of nitrogen (N), maximum biomass yield of leaves was observed with N3 (11.63 tonnes ha?1) ≥ N2 (11.64 tonnes ha?1), followed by N1(8.96 tonnes ha?1) with the highest yield (19.97 tonnes ha?1) registered through the combination of M3N3. Treatment combination M3N3 in turn maintained higher fungal (118 × 102 vs. 31 × 102 with M0N0 c.f.u.g?1 soil) and bacterial populations (48 × 105 vs. 31 × 103 with M0N0 c.f.u.g?1 soil) for better nutrient acquisition through improvements in the concentration of soil available nutrients. These responses consequently improved the oil concentration in leaves (3.65% with M3N3 vs. 2.40% with M0N0) and alcohol (49.90% with M3N3 vs. 44.52% in M0N0) as quality indices. This research verified that the quality of patchouli leaves as an intercrop was raised, besides improving coconut yield (40–55 nuts palm?1) as main crop, when utilizing combined treatments of vermicompost enriched with inorganic N under coconut-patchouli farming systems.  相似文献   

13.
ABSTRACT

The effect of deficit irrigation (DI) on wheat crop yield, soil physical parameters and on nitrate nitrogen movement in soil profile was evaluated under application of dairy manure and nitrogen fertilizer. Two levels of DI were taken as I0.6 (60% FC) and I0.8 (80% FC) along with two dairy manure levels (20 and 25 Mg ha?1) and three nitrogen levels (80, 100, and 120 kg ha?1). The grain yield was high under I0.8 than I0.6, whereas the irrigation level has no significant effect on soil organic carbon contents. Dairy manure, irrigation, and nitrogen indicated strong interaction with each other for all yield-related parameters during both years of study, however, results for 2nd year were highly positive. Soil nitrate nitrogen movement was significantly affected under I0.8 with high rate of dairy manure (25 Mg ha?1) and nitrogen fertilizer (120 kg ha?1). Results concluded that combined application of dairy manure (25 Mg ha?1) and nitrogen fertilizer (120 kg ha?1) under DI level I0.8 resulted in high grain yield. To overcome water scarce conditions, further experiments can be designed by addition of various organic matters in different combination that enhances the yield and soil health.  相似文献   

14.
Two vermicompost treatments providing 45 (V1) and 90 (V2) kg P ha?1 and mycorrhizae (M) inoculation were evaluated alone and in combinations for wheat (Triticum aestivum L.) growth and soil fertility status. The treatments included; the Control, nitrogen (N): dipotassium oxide (K2O) as basal dose (BD; 120:60 kg ha?1), N: phosphorus pentoxide (P2O5): K2O as recommended dose (RD; 120:90:60 kg ha?1), BD+Myccorhiza (BDM), BD+V1 (BDV1), BDM+V1 (BDMV1), BD+V2 (BDV2), and BDM+V2 (BDMV2). Combination of mycorrhizae and vermicompost (BDMV1 and BDMV2) significantly and maximally improved the growth, plant N, phosphorus (P), and micronutrient concentrations over the control, reduced the soil pH by 5 and 6%, increased OM by 25 and 112%, total N by 41%, and extractable P up to 200% while the extent of improvement was directly related to the content of added vermicompost. Results indicated that vermicompost at either level synergistically affected the mycorrhizae in plant nutrition as well as improved soil fertility status and soil chemical properties.  相似文献   

15.
ABSTRACT

The interactive effect of biochar, cattle manure and nitrogen (N) fertilizer on the dynamics of carbon (C) mineralization and stabilization was investigated in a sandy soil amended with three sole biochar (0, 20 or 40 t ha?1) or manure (0, 13 or 26 t ha?1) and four combined biochar-manure levels (20 or 40 t ha?1 biochar plus 13 or 26 t ha?1 manure) with or without N fertilizer (0 or 90 kg ha?1) and CO2-C evolution measured over 54-d incubation period. Biochar application, solely or combined with manure resulted in lower applied C mineralized (ACM), indicating C sequestration in the soils. Negative attributable effect (AE) of co-application of biochar and manure on C mineralization was observed relative to the sole treatments. Both ACM and AE were negatively correlated with C/N ratio and mineral N content of the soil-mixtures (r ≥ – 0.573; p ≤ 0.01), indicating microbial N limitation. The double first-order exponential model described CO2-C efflux very well and indicated that ≥94% of C applied was apportioned to stable C pools with slower mineralization rate constant and longer half-life. Cumulative C mineralized and modeled C pools were positively correlated with each other (r ≥ 0.853; p ≤ 0.001) and with readily oxidizable C of soil-amendment mixtures (r ≥ 0.861; p ≤ 0.001). The results suggested that co-application of biochar and manure can promote initial rapid mineralization to release plant nutrients but sequester larger amounts of applied C in refractive C pool, resulting in larger C sequestration in sandy soils.  相似文献   

16.
An experiment was conducted to study the response of maize to magnesium (Mg) and to find out the residual effect of Mg and green manure (GM) on transplanted aman (T. aman) rice in the maize–GM–T. aman cropping pattern. There were six treatments: T1 (recommended dose of fertilizer (RDF) + 0 kg Mg + 2 t CaCO3 ha?1), T2 (RDF + 10 kg Mg + 2 t CaCO3 ha?1), T3 (RDF + 20 kg Mg +2 t CaCO3 ha?1), T4 (RDF + 30 kg Mg + 2 t CaCO3 ha?1), T5 (RDF) and T6 (2 t CaCO3 ha?1). The response of maize to Mg was quadratic and the optimum dose of Mg was found to be 19 kg ha?1, which resulted in maximum yield of 10,507 kg ha?1. The residual effect of Mg along with GM and reduced dose of chemical fertilizer resulted in significant increase of grain yield of rice. Thus, N250P60K100Mg19S40Zn5B2 kg ha?1 for maize, only 20 kg N ha?1 for GM (Sesbania) and N60P9K33S10Zn1B1 kg ha?1 for T. aman appeared as the best combination for maximizing the productivity and may be recommended for this pattern at non-calcareous light-textured soils of Bangladesh. Application of lime increased soil pH, and this together with fertilizer and GM tended to improve soil fertility and thus may be recommended for soil amelioration.  相似文献   

17.
It was hypothesized that the application of eucalyptus biochar enhances nutrient use efficiencies of simultaneously supplied fertilizer, as well as provides additional nutrients (i.e., Ca, P, and K), to support crop performance and residual effects on subsequent crops in a degraded sandy soil. To test this hypothesis, we conducted an on‐farm field experiment in the Khon Kaen province of Northeastern Thailand to assess the effects of different application rates of eucalyptus biochar in combination with mineral fertilizers to upland rice and a succeeding crop of sugarcane on a sandy soil. The field experiment consisted of three treatments: (1) no biochar; (2) 3.1 Mg ha?1 biochar (10.4 kg N ha?1, 3.1 kg P ha?1, 11.0 kg K ha?1, and 17.7 kg Ca ha?1); (3) 6.2 Mg ha?1 biochar (20.8 kg N ha?1, 6.2 kg P ha?1, 22.0 kg K ha?1, and 35.4 kg Ca ha?1). All treatments received the same recommended fertilizer rate (32 kg N ha?1, 14 kg P ha?1, and 16 kg K ha?1 for upland rice; 119 kg N ha?1, 21 kg P ha?1, and 39 kg K ha?1 for sugarcane). At crop harvests, yield and nutrient contents and nitrogen (N) use efficiency were determined, and soil chemical properties and pH0 monitored. The eucalyptus biochar material increased soil Ca availability (117 ± 28 and 116 ± 7 mg kg?1 with 3.1 and 6.2 Mg ha?1 biochar application, respectively) compared to 71 ± 13 mg kg?1 without biochar application, thus promoting Ca uptake and total plant biomass in upland rice. Moreover, the higher rate of eucalyptus biochar improved CEC, organic matter, available P, and exchangeable K at succeeding sugarcane harvest. Additionally, 6.2 Mg ha?1 biochar significantly increased sugarcane yield (41%) and N uptake (70%), thus enhancing N use efficiency (118%) by higher P (96%) and K (128%) uptake, although the sugar content was not increased. Hence, the application rate of 6.2 Mg ha?1 eucalyptus biochar could become a potential practice to enhance not only the nutrient status of crops and soils, but also crop productivity within an upland rice–sugarcane rotation system established on tropical low fertility sandy soils.  相似文献   

18.
Application of crop residues and its biochar produced through slow pyrolysis can potentially increase carbon (C) sequestration in agricultural production systems. The impact of crop residue and its biochar addition on greenhouse gas emission rates and the associated changes of soil gross N transformation rates in agricultural soils are poorly understood. We evaluated the effect of wheat straw and its biochar applied to a Black Chernozemic soil planted to barley, two growing seasons or 15 months (at the full-bloom stage of barley in the second growing season) after their field application, on CO2 and N2O emission rates, soil inorganic N and soil gross N transformation rates in a laboratory incubation experiment. Gross N transformation rates were studied using the 15N isotope pool dilution method. The field experiment included four treatments: control, addition of wheat straw (30 t ha?1), addition of biochar pyrolyzed from wheat straw (20 t ha?1), and addition of wheat straw plus its biochar (30 t ha?1 wheat straw + 20 t ha?1 biochar). Fifteen months after their application, wheat straw and its biochar addition increased soil total organic C concentrations (p?=?0.039 and <0.001, respectively) but did not affect soil dissolved organic C, total N and NH4 +-N concentrations, and soil pH. Biochar addition increased soil NO3 ?-N concentrations (p?=?0.004). Soil CO2 and N2O emission rates were increased by 40 (p?p?=?0.03), respectively, after wheat straw addition, but were not affected by biochar application. Straw and its biochar addition did not affect gross and net N mineralization rates or net nitrification rates. However, biochar addition doubled gross nitrification rates relative to the control (p?2 and N2O emissions and enhance soil C sequestration. However, the implications of the increased soil gross nitrification rate and NO3 ?-N in the biochar addition treatment for long-term NO3 ?-N dynamics and N2O emissions need to be further studied.  相似文献   

19.
Reclamation of sodic soils is proving increasingly vital as greater land area becomes salt-affected in the northern Great Plains of the United States. Flue gas desulfurization gypsum (FGDG) can be an agriculturally important resource for increasing land productivity through the amelioration of sodic soils. Biochar is also considered as an aid in reclaiming degraded soils. In this incubation study, two rates of FGDG (33.6 Mg ha?1 and 66.2 Mg ha?1), two rates of biochar made from sugar beet (Beta vulgaris L.) pulp (16.8 Mg ha?1), and one rate of FGDG combined with one rate of biochar (33.6 Mg ha?1 ea.) were applied to a sodic soil. Soil physicochemical properties, including cationic exchange, pH, electrical conductivity (ECe), sodium adsorption ratio (SARe), total organic carbon (TOC), water retention, and soil respiration rate, were assessed during and at the end of the incubation period. Addition of FGDG to sodic soil increased ECe from 3.5 to 8.4 dS m?1 and decreased SARe from 16 to 9. Biochar addition to sodic soil increased TOC from 62.2 to 99.5 μg g?1 and increased soil respiration rate (mg C kg?1 soil day?1) on every measurement period. When FGDG and biochar were both added to the sodic soil, TOC did not significantly improve; however, ECe increased from 3.5 to 7.7 dS m?1, SARe decreased from 16 to 9, and soil respiration rate increased for all measurements. The results confirm there is potential for FGDG and biochar to reclaim sodic soils alone, and applied in combination.  相似文献   

20.
This study investigated the impacts of organic- and clay-based soil amendments, and their combinations on crop water productivity (CWP) using maize as a test crop. On-station field trials were established over two consecutive years at the Naphok and Veunkham sites in Laos. At each site, 10 treatments were applied in a randomized complete block design with three replications. The treatments were control, rice husk biochar (10 t ha?1), bentonite clay (10 t ha?1), compost (4 t ha?1), clay-manure compost (10 t ha?1), rice husk biochar compost (10 t ha?1), bentonite clay + biochar, bentonite-clay + compost, biochar + compost, and bentonite clay + biochar + compost. All treatments were applied in 2011. Significant (p < 0.05) treatment effects in CWP and growing period evapotranspiration were determined. At Naphok, differences between the amended and control plots in CWP varied between 0.1 and 0.6 kg m?3 in 2011 and from 0.1 to 0.4 kg m?3 in 2012, whereas differences at Veunkham varied between 0.3 and 1.0 kg m?3 in 2011 and from 0.05 to 0.29 kg m?3 in 2012. At both sites, CWP in 2012 was significantly lower than 2011. Our results illustrate that organic- and clay-based soil amendments improve CWP, indicating that soil-based interventions could be suitable options for improving agricultural productivity.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号