Mitigation of N_(2)O emissions in water-saving paddy fields:Evaluating organic fertilizer substitution and microbial mechanisms

Water-saving irrigation strategies can successfully alleviate methane emissions from rice fields,but significantly stimulate nitrous oxide(N_(2)O)emissions because of variations in soil oxygen level and redox potential.However,the relationship linking soil N_(2)O emissions to nitrogen functional genes during various fertilization treatments in water-saving paddy fields has rarely been investigated.Furthermore,the mitigation potential of organic fertilizer substitution on N_(2)O emissions and the microbial mechanism in rice fields must be further elucidated.Our study examined how soil N_(2)O emissions were affected by related functional microorganisms(ammonia-oxidizing archaea(AOA),ammonia-oxidizing bacteria(AOB),nirS,nirK and nosZ)to various fertilization treatments in a rice field in southeast China over two years.In this study,three fertilization regimes were applied to rice cultivation:a no nitrogen(N)(Control),an inorganic N(Ni),and an inorganic N with partial N substitution with organic manure(N_(i)+N_(o)).Over two rice-growing seasons,cumulative N_(2)O emissions averaged 0.47,4.62 and 4.08 kg ha^(−1)for the Control,Ni and N_(i)+N_(o)treatments,respectively.In comparison to the Ni treatment,the N_(i)+N_(o)fertilization regime considerably reduced soil N_(2)O emissions by 11.6%while maintaining rice yield,with a lower N_(2)O emission factor(EF)from fertilizer N of 0.95%.Nitrogen fertilization considerably raised the AOB,nirS,nirK and nosZ gene abundances,in comparison to the Control treatment.Moreover,the substitution of organic manure for inorganic N fertilizer significantly decreased AOB and nirS gene abundances and increased nosZ gene abundance.The AOB responded to N fertilization more sensitively than the AOA.Total N_(2)O emissions significantly correlated positively with AOB and nirS gene abundances while having a negative correlation with nosZ gene abundance and the nosZ/nirS ratio across N-fertilized plots.In summary,we conclude that organic manure substitution for inorganic N fertilizer decreased soil N_(2)O emissions primarily by changing the soil NO_(3)^(−)-N,pH and DOC levels,thus inhibiting the activities of ammonia oxidation in nitrification and nitrite reduction in denitrification,and strengthening N_(2)O reduction in denitrification from water-saving rice paddies.

Effects of Integrated Organic and Inorganic Fertilizers on Yield and Growth Parameters of Rice Varieties

We investigated the effects of integrated organic and inorganic fertilizers on the growth and yield of indica rice variety Manawthukha and japonica rice variety Genkitsukushi.In a split-plot design,the two rice varieties were assigned as main plot factors,and the integrated treatments were the subplot factors,including no-N fertilizer(N0),50%chemical fertilizer(CF)(CF50),100%CF(CF100),50%CF+50%poultry manure(PM)(CF50PM50),50%CF+50%cow manure(CM)(CF50CM50),and 50%CF+50%compost(CP)(CF50CP50).CF100 was equivalent to N at 85 kg/hm2.Manure was applied based on the estimated mineralizable nitrogen(EMN)level,which is dependent on total N(%)of each manure type.Manawthukha rice plants were taller with higher tiller number and dry matter content.However,higher soil-plant analysis development(SPAD)values were measured in Genkitsukushi throughout the crop growth period,resulting in higher seed-setting rate(%)and greater yield.At the same N level,CF50PM50 application in both rice varieties resulted in higher SPAD values,plant height and tiller number than CF100.CF50PM50 containing total N more than 4%supplied synchronized N for the demands of the rice plants,resulting in maximum dry matter,yield and yield components.CF50CM50 and CF50CP50 treatments containing total N less than 4%resulted in lower yields which were similar to CF100.These results indicated that integrating organic and inorganic fertilizers enhanced growth parameters and yields of Manawthukha and Genkitsukushi,while reducing the dose of chemical fertilizer.

Combined Application of Organic and Inorganic Fertilizers on Black Soil Fertility and Maize Yield

By two years （2007-2008） located fertilizer experiment, the effect of long-term combined application of organic and inorganic fertilizers on black soil fertility and crop yield was investigated in Shuangcheng City, Heilongjiang Province. The results showed that the combined application of organic and inorganic fertilizers could increase the organinc matter, alkaline nitrogen, available phosphorus and available potassium. At the same time, the increasing application of organic fertilizer could reduce the soil bulk density and improve the field moisture capacity. Field moisture capacity and organic matter of the combined application of high quantities of organic manure and inorganic fertilizers AtB5 treatment increased the fhstest, organic matter increased by 3.33 g. kg and field moisture capacity increased by 11.25% than the beginning of the experiment. Under the same fertilization, the combined application of organic and inorganic fertilizers＇ increasing production range was higher than the single chemical fertilizers＇ which was from 0.8% to 9.4%. The results showed that the combined application of organic and inorganic fertilizers could increase the nutrient contents of soil and also was the highest productivity contribution to black soil fertility. It was the best fertilization structure of increasing productivity level and improving the soil fertility.

Combined Effect of Organic Manures and Inorganic Fertilizers on the Growth and Yield of Hybrid Rice (Palethwe-1)

We investigated the effect of combining organic and inorganic fertilizers on the growth and yield of hybrid rice (Palethwe-1) in the dry and wet seasons of 2015. Four quantities of inorganic fertilizer were used in the main plot [0%, 50%, 75%, and 100% nitrogen, phosphorus, and potassium (NPK)] based on the recommended amounts of 150 kg N ha-1, 70 kg P2O5 ha-1, and 120 kg K2O ha-1, while different organic manures were applied to subplots [no organic manure (O0), cow manure (Oc), poultry manure (Op), and vermicompost (Ov);all at 5 t·ha-1] as part of a split-plot experimental design with three replicates. In both seasons, significant differences in growth parameters including number of tillers hill-1, soil-plant analysis development (SPAD) values, total dry matter, yield, and yield components were observed in plants supplied with different inorganic fertilizers. The 100% NPK (I100) fertilizer produced the maximum yield but similar yields were achieved in plots supplied with 50% NPK (I50) and 75% NPK (I75). Significant differences in growth and yield parameters were also found in crops supplied with organic manures. Although identical quantities were supplied, Op produced the best growth parameters in both seasons including total dry matter, yield, and yield components. Oc also performed well. Combining inorganic and organic fertilizers demonstrated that I50 together with Op (5 t·ha-1) provided similar growth, total dry matter, and yield parameters to I100 in both seasons. Oc (5 t·ha-1) plus I75 also achieved similar yields to I100. This study demonstrates that the combined application of inorganic fertilizers and organic manures has the potential to reduce chemical fertilizer usage without decreasing the yield of hybrid rice, and can enhance the growth, yield, and yield components of Palethwe-1.

Evaluation of Economic Importance of Locally Produced Manure over Inorganic Fertilizer for Maize Production: Vegetative Performance and Cost Implication

Background: Crops of economic importance like Maize are preferred to other crops with capacity of giving the highest yields, having the ability to help alleviate poverty within the African continent. The consistent use of inorganic fertilizers has great adverse effect on soil structure. The quest to seek alternative method of boosting maize production is imminent to avoid further soil degradation. Most plants form symbiotic relationships with mycorrhizae and improve nutrients uptake by host plants. Objectives: The aim of this study is to examine the effect of mycorrhizae in local manure production on development of maize, in comparison with inorganic fertilizer application and its cost implication. Methods: The experiment involved samples of starter soil from 7 local governments. Organic waste was added to starter soil, each having three replicates. Nine other replicates served as non-inoculated controls and nine served for fertilizer application at 50 g, 100 g and 150 g. One [1] gram of Maize sown in 50 ml pot contains soil at different treatment levels 50 g, 100 g, and 150 g. After two weeks, samples were transplanted in an open field. Results: The result showed plots treated with locally produced fertilizer, significantly influenced plant height, culm diameter, number of leaves and leaf broadness in comparison to inorganic fertilizer, which showed 53%, 47% respectively. Conclusion: Cost production of a bag of organic fertilizer was one-fourth cheaper compared to an inorganic fertilizer price from an open market.

Changes of Organic Matter, N, P and K Content of Soils in Red Soil Areas Under Long-Term Experiment

The content of organic matter （OM）, nitrogen （N）, phosphorus （P）, and potassium （K） in the three selected soils, including Calcaric Purpli-Orthic Primosols （purple sand-shale parent material）, Dystric Turbi-Anthric Primosols （quaternary red clay parent material） and Typic Udi-Sandic Primosols （granite parent material） were studied under a long-term experiment by using crop straw and inorganic fertilizers at the Hunan Red Soil Experiment Station of Chinese Academy of Agricultural Sciences. The results showed that the contents of OM, N, P and K in the three selected soils increased after 23 years application of crop straw and inorganic fertilizers, but the contents increased much less when crop straw or inorganic fertilizers was applied alone. The nutrient contents in the three soils developed from granite changed more remarkably than those in the soil derived from quaternary red clay and purple sand-shale. It was also found that the contents of OM, N, and P increased slightly in the treatments without applying fertilizers or returning the crop straw to the root bed. Combined application of inorganic fertilizers and crop straw could remarkably increase the contents of OM, alkalihydrolyzable N and available K, the positive correlation between application of organic fertilizers and increase of OM in soil did not always happened, it provided evidence for the relation between appropriate C/N ratio and accumulation of OM in soil. The increase of nutrient content was influenced by the soil properties. By comparing the contents of nutrient in 0-20 cm depth in the three different soils, it was concluded that the most increases of OM, alkali-hydrolyzable N, and available P were observed in Typic Udi-Sandic Primosols with the average increase by 3.03, 27.38, and 21.73 mg kg^-1, respectively. The available K increased in Dystric Turbi-Anthric Primosols with the average increase by 25.82 mg kg^-1, while it decreased in Calcaric Purpli-Orthic Primosols and Typic Udi-Sandic Primosols. It was concluded that the application of inorganic fertilizer and crop straw was important to improve the soil fertility for all of three selected soils. The straw return to the field had played a significant role for enhancement of the soil quality in the study areas. The application of inorganic fertilizer combined with the straw return to the fields could remarkably improve the soil fertility.

The Application of Fertilizer and AMF Promotes Growth and Reduces the Cadmium and Lead Contents of Ryegrass (Lolium multiflorum L.) in a Copper Mining Area

Heavy metal-polluted soil was collected from the Pulang copper mine in Shangri-La City,Yunnan Province,Southwest China.The effects of fertilizer(organic and inorganic)and arbuscular mycorrhizal fungi(AMF)on ryegrass(Lolium multiflorum L.)growth,root morphology,mineral nutrition and cadmium(Cd)and lead(Pb)contents were investigated by pot experiments.The results showed that both fertilizer and AMF significantly ameliorated the root morphology and mineral nutrition,reduced the Cd and Pb contents,and promoted the growth of ryegrass.Among all treatments,the combined application of organic–inorganic compound fertilizer with AMF had the highest effect,resulting in increases in root length,surface area and branch number by 2.3,1.1,and 3.9 times,respectively;an 88%increase in plant biomass;a nitrogen content increase of 2.3 and 1.2 times,and phosphorus content increase of 62%and 68%in shoots and roots,respectively was also recorded as well as decreases in Cd content by 34%and 62%and Pb content by 47%and 34%in shoots and roots,respectively.Twofactor analysis showed that both fertilizer and AMF significantly promoted ryegrass growth(plant height,biomass,chlorophyll content,root length,nitrogen and phosphorus content)and reduced the Cd and Pb contents in roots,and there was a synergistic effect between them.Moreover,the nitrogen and phosphorus contents were very significantly positively correlated with the shoot and root biomasses but very significantly negatively correlated with the Cd and Pb contents of ryegrass.Thus,the application of fertilizer and AMF synergistically improved ryegrass growth on polluted soils in the copper mining area.

Growth, Yield and Yield Characteristics of Three Pepper Cultivars to Fertilizers Application in the Mount Cameroon Region

This study determined the effects of organic and inorganic fertilizers on growth and yield of three pepper cultivars in the Mount Cameroon Region. Pepper seedlings were treated with six treatments (T1 = no fertilizers (control), T2 = 250 Kg/ha NPK 20:10:10, T3 = 350 Kg/ha NPK 20:10:10, T4 = 450 Kg/ha NPK 20:10:10, T5 = 20 Mg/ha poultry manure (PM), T6 = 30 Mg/ha PM). The effects of fertilizers had a significant effect on vegetative growth and yield of Capsicum chinense cv. “Big Sun” plants had the maximum plant height (39.09 cm) and mean collar diameter (6.02 mm) in plots treated with poultry manure at 20 Mg/ha (T5) and 30 Mg/ha (T6) respectively. The highest yield (33.63 Mg/ha) was in Capsicum chinense cv. Safi plants supplied with 30 Mg/ha poultry manure (T6) and the lowest yield (10.44 Mg/ha) was in Capsicum frutescens in control plots (T1). The highest fruit diameter (11.08 mm) and longest fruits (18.39 mm) were observed in Capsicum chinense cv. Big Sun plants supplied with 30 Mg/ha poultry manure. Capsicum frutescens fruits had the highest concentration of N (2.39%), P (0.42%) and K (3.06%). Essential oils analysis shows that there were 179 essential oils from pepper fruits of Capsicum chinense cv. Safi, with major essential oil been 3,4-dimethyl-benzaldehyde and main essential oils were alpha Terpinene and alpha Pinene based on their abundance. Fruits of Capsicum chinense cv. Big Sun had two-hundred and eight essential oils with major essential oil been 1,3,5-Trimethyl-1-H-pyrazol-4-amine and main essential oils were Caryophyllene oxide and Cymene, based on their abundance. Fruits of Capsicum frutescens had one-hundred and eighty-one essential oils with major essential oil been Limonene, and main essential oils were Carvacrol and D-limonene with respect to abundance. Results show that 20 Mg/ha poultry manure was the most cost effective in the production of pepper in Buea Cameroon.

Effect of N Fertilizers on Root Growth and Endogenous Hormones in Strawberry

Endogenous hormones play an important role in the growth and development of roots. The objective of this research was to study the effect of four types of N fertilizers on the root growth of strawberry (Fragaria ananassa Duchesne) and the endogenous enzymes of indole-3-acetic acid (IAA), abscisic acid (ABA), and isopentenyl adenosine (iPA) in its roots and leaves using enzyme-linked immunosorbent assay. Application of all types of N fertilizers significantly depressed (P ≤ 0.05) root growth at 20 d after transplanting. Application of organic-inorganic fertilizer (OIF) as basal fertilizer had a significant negative effect (P ≤ 0.05) on root growth. The application of OIF and urea lowered the lateral root frequency in strawberry plants at 60 d (P ≤ 0.05) compared with the application of two organic fertilizers (OFA and OFB) and the control (CK). With the fertilizer treatments, there were the same concentrations of IAA and ABA in both roots and leaves at the initial growth stage (20 d), lower levels of IAA and ABA at the later stage (60 d), and higher iPA levels at all seedling stages as compared to those of CK. Thus, changes in the concentrations of endogenous phytohormones in strawberry plants could be responsible for the morphological changes of roots due to fertilization.

Effect of Land Use Conversion from Rice Paddies to Vegetable Fields on Soil Phosphorus Fractions

Excess phosphorus （P） from agricultural soils contributes to eutrophication in water bodies. Samples （n = 60） were taken from sites where rice paddies have been converted to vegetable fields for 0, 〈 10, 10-20, and 〉 20 years and analyzed for five inorganic P （Pi） fractions, three organic P （Po） fractions, and several soil parameters to investigate how land use conversion affects Pi and Po fractions in a peri-urban area of China with soils characteristic of many agricultural areas of Asia. Significant increases of 33, 281, 293, and 438 mg kg-i were found for soluble and loosely bound Pi （SL-Pi）, aluminum-bound Pi （Al-Pi）, calcium-bound Pi （Ca-Pi）, and iron-bound Pi （Fe-Pi）, respectively, after conversion from rice paddies to vegetable fields. Most of the increase in Pi was in the form of Fe-Pi, which increased from 8% of total P （TP） on paddy soil to 31% on the soil with 〉 20-year vegetable cultivation, followed by Al-Pi, which increased from 2% to 19% of TP. For Po fractions, there was no significant change in P concentrations. The conversion of land use from paddy fields to high intensity vegetable fields was causing significant changes in soil P fractious. Management practices were causing a buildup of soil P, primarily in the Fe-Pi fraction, followed by Ca-Pi and Al-Pi fractions. If current trends continue, a 30%-70% increase in TP could be expected in the next 20 years. Farmers in the area should reduce P application and use to maximize P uptake.

The Impacts on Spinach Growth and Yield by Biological Organic Fertilizer

To decrease fertilization amount of chemical fertilizer and improve the quality of vegetable crops,spinach was taken as the test material,and the impact of different fertilizer on spinach growth and yield was studied via the manners of biological organic fertilizer and organic fertilizer + chemical fertilizer. Experimental results showed that in the formula of organic fertilizer + chemical fertilizer,chlorophyll and nitrogen contents in spinach leaves obviously increased; in the formula of only adding organic fertilizer,spinach leaf temperature,leaf width,root length,plant height and fresh weight were all better than those in the formula of organic fertilizer + chemical fertilizer,and better formulas were A_5,E_5,F_3 and I_5,in which spinach plant height in E_5 was 5. 63 times higher than G_5,root length in E_5 was 2. 67 times higher than G_5,and fresh weight in G_5 was 32. 6 times higher than G_5. By comprehensive analysis,the most suitable formula for spinach production was E_5,and the research could provide theoretic basis for fertilization amount of organic fertilizer required by spinach growth and development.

有机-无机复混肥施用对广西典型烟田土壤肥力及烟草品质的影响

采用田间试验并选择典型高肥力、低肥力烟田土壤,设置茶籽粕+无机肥(T)、菜籽粕+无机肥(R)和花生粕+无机肥(P)3个处理,研究有机-无机复混肥施用对广西典型烟田土壤肥力和烟草品质的影响。结果表明:有机-无机复混肥施用可提高土壤微生物活性,加速有机物料矿化,促进土壤速效养分积累,改善土壤结构,尤其在低肥力水平下花生粕的添加表现最为明显;能促进总糖、钾、氯等元素在烟草中的积累,但有机物料添加对烟草品质的影响明显低于初始肥力烟田土壤。高肥力土壤有助于烟草中钾、氯等元素积累,但总糖、还原糖、糖碱比均显著低于低肥力烟田土壤。针对烟草工业需求,在实际生产中应重点关注中、低产田土壤,结合肥料调控开展优质烟叶原料生产。

减量灌水及有机无机肥配施对西北灌区玉米光合生理、籽粒产量及品质的影响

针对绿洲灌区玉米生产中普遍水肥投入大、利用效率低等问题,通过研究不同灌水量和有机无机肥等氮配施对玉米光合生理、籽粒产量和品质的影响,以期获得最佳的灌水水平和有机无机肥等氮配施比例。2021—2022年,在绿洲灌区采用两因素裂区试验设计,主区为2个灌水水平(传统灌水和减量20%灌水),副区为5个有机无机肥等氮配施比例(全施无机氮肥、75%无机氮肥+25%有机肥、50%无机氮肥+50%有机肥、25%无机氮肥+75%有机肥和全施有机肥),探究玉米光合生理、籽粒产量和品质对不同水氮管理模式的响应特征。结果表明,与传统灌水(I2)相比,减量20%灌水(I1)降低了玉米叶面积指数(leaf area index,LAI)、光合势(photosynthetic potential,LAD)、净光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Gs),提高了胞间CO_(2)浓度(Ci)、籽粒蛋白质含量和籽粒苏氨酸含量;有机无机肥配施对玉米光合生理指标、籽粒产量和品质都有显著影响,随有机肥比例增加,有机无机肥配施对玉米的影响会逐渐从正效应变为负效应;与传统灌水结合全施无机氮肥(I2F1)相比,减量20%灌水结合75%无机氮肥+25%有机肥(I1F2)玉米平均叶面积指数(mean leaf area index,MLAI)提高了6.9%~7.1%,总光合势(total photosynthetic potential,TLAD)无显著变化;玉米吐丝期-蜡熟期LAI提高了5.0%~11.4%,吐丝期-蜡熟期LAD提高了7.5%~9.1%。I1F2较I2F1提高了玉米抽雄期-蜡熟期叶绿素含量(chlorophyll content,SPAD)、Pn、Tr和Gs,降低了Ci。2年内I1F2较I2F1玉米增产12.0%~12.5%,籽粒中蛋白含量提高了6.9%~18.9%,籽粒中苯丙氨酸、赖氨酸、苏氨酸、色氨酸、亮氨酸、异亮氨酸和缬氨酸含量分别提高了29.6%~43.3%、77.7%~93.3%、49.7%~51.5%、18.4%~28.6%、39.5%~46.0%、57.4%~78.1%和35.1%~41.3%。其他处理对玉米光合生理、籽粒产量及品质指标也有一定影响,但综合2年结果,I1F2影响更显著。因此,减量20%灌水(3240 m^(3)hm^(–2))结合75%无机化学氮肥(270 kg hm^(–2))配施25%有机肥(90 kg hm^(–2))是实现西北灌区玉米高产优质生产目标的适宜水氮管理模式。

有机无机复混肥料对水稻产量及养分吸收利用的影响

为了提高水稻肥料利用率,减少化肥施用量,研究有机无机复混肥的施用效果,设置不施肥(CK)、常规施肥(普通复合肥,氮肥分次施用)(FFP)、等养分有机无机复混肥(一次性施肥)(T1)、等养分有机无机复混肥(氮肥分次施用)(T2)、90%养分有机无机复混肥(氮肥分次施用)(T3)、80%养分有机无机复混肥(氮肥分次施用)(T4)共6个处理,研究有机、无机肥配施对水稻产量及氮磷吸收利用的影响。各处理花后干物质积累量对籽粒贡献率(62.7%~68.5%)均高于干物质转运量对籽粒贡献率(31.5%~37.3%);各处理的实际产量表现为T2>T1>FFP>T3>T4>CK,与FFP处理相比,T2和T1处理增产6.6%和2.2%,T3和FFP处理产量无显著差异;成熟期各处理水稻植株地上部氮素和磷素吸收积累量在籽粒部分占比达到65%和70%以上,与FFP处理相比,T1处理氮磷肥吸收利用率、氮磷肥农学利用率和氮磷肥偏生产力分别增加了8.9%和12.9%、0.9%和3.2%、0.9和3.2 kg·kg^(-1),T2处理氮磷肥吸收利用率、氮磷肥农学利用率和氮磷肥偏生产力分别增加了1.6%和1.6%、2.6%和9.6%、2.6和9.6 kg·kg^(-1),T3和T4处理与FFP处理差异不显著。有机、无机肥配施能提高氮磷养分吸收利用率,在氮磷钾总养分相同的情况下,一次性施用有机无机复混肥更有利于提高水稻氮磷吸收,在氮肥分次施用情况下,有机无机复混肥增产效果更明显,适当减肥不会降低水稻产量,还可以减少稻田养分残留。

有机无机肥配施菌剂对葡萄园土壤、果实及葡萄酒品质的影响

为了减少化肥施用量,充分发挥有机肥效应并有效提高酿酒葡萄果实品质,试验设置不施肥对照(CK)、100%化肥(C_(1))、100%有机肥(O_(1))、100%有机肥+菌剂(O_(1)B)、60%化肥+40%有机肥(C_(0.6)O_(0.4))、60%化肥+40%有机肥+菌剂(C_(0.6)O_(0.4B))6个处理,除CK外,各施肥处理的氮、磷、钾养分含量一致,研究不同处理对赤霞珠葡萄园土壤养分、果实及葡萄酒基本理化性质以及酚类物质积累的影响,分析土壤环境因子与葡萄及葡萄酒品质指标的相关性,以期为酿酒葡萄的科学高效施肥提供参考依据。结果表明:与CK处理相比,O_(1)和C_(0.6)O_(0.4)处理的土壤有机质、全氮、全钾、速效钾和可溶性有机碳含量分别提高30.22%和70.65%、27.45%和31.37%、10.10%和20.11%、438.93%和491.60%。与C_(1)处理相比,有机肥配施菌剂处理(O_(1)B、C_(0.6)O_(0.4B))土壤有机质、全氮、全钾、速效钾含量分别提高了101.30%和104.78%、27.45%和47.06%、13.58%和23.12%、2.23%和15.81%。有机肥配施菌剂可显著提升葡萄园土壤肥力;与CK相比,C_(0.6)O_(0.4B)处理的葡萄果实总可溶性固形物、还原糖、糖酸比分别提高了4.93%、10.35%和49.78%;葡萄酒酒度提高了6.67%、总酸含量降低了7.93%;果皮总酚和总花色苷含量分别提高了26.98%和19.56%,葡萄酒总酚和总花色苷含量分别提高了11.13%和56.98%;冗余度分析和Spearman相关系数表明,酿酒葡萄果实和葡萄酒品质指标的变化与土壤环境因子(有机质、硝态氮、铵态氮、速效钾、有效磷)密切相关,证实了生物菌剂和有机肥共施可提高酿酒葡萄品质。综合比较,施用有机肥及菌剂可以改善土壤性状及酿酒葡萄品质,进而提高葡萄酒口感和色泽品质,其中减施化肥配施有机肥和菌剂(C_(0.6)O_(0.4B))效果最好。

有机无机肥配施对西北地区不同土壤类型氮素矿化影响

为揭示不同施肥措施和土壤类型对我国西北地区典型农田土壤氮素矿化特征的影响,通过室内恒温好气培养法,分别研究不施肥(CK)、单施尿素(U)、单施有机肥(M)和尿素配施有机肥(U+M)施肥模式对土壤氮素矿化动态过程的影响,并对土壤累积矿化氮量进行一级动力学方程拟合及相关性分析。结果表明,施肥和土壤类型均显著影响土壤铵态氮含量、硝态氮含量和累积矿化氮量,且两者之间存在显著的交互作用。不同类型土壤累积矿化氮量和矿化速率由大到小依次为塿土、黄绵土、黄河灌淤土、灰棕漠土。与CK处理相比,不同施肥处理显著增加土壤累积矿化氮量、矿化速率常数(k)和矿化势(N0),处理间差异显著(P<0.05)。单施尿素和尿素配施有机肥处理的累积矿化氮量和矿化速率分别较CK处理增加2.83~6.71倍和3.83~7.70倍。相关分析表明,土壤累积矿化氮量与土壤有机质含量和全氮含量呈显著正相关关系。研究结果表明,有机无机肥配施处理可显著促进西北地区不同土壤类型氮素矿化,提高氮素有效性和供氮能力,有利于保持土壤矿质氮含量,对农田氮素高效利用有重要作用。

微波消解-电感耦合等离子体质谱法测定肥料中9种污染元素

采用电感耦合等离子体质谱法(ICP-MS)测定,超级微波消解并优化不同类型肥料的消解条件,建立了超级微波-ICP-MS测定多种类型肥料中V、Cr、Co、Ni、As、Cd、Hg、Tl、Pb 9种污染元素含量的方法。本方法的线性相关系数均大于0.9999,方法检出限范围为0.000500~0.0293 mg/kg,各元素加标回收率为85.0%~110%,该方法灵敏度高、准确度较好,可实现不同类型肥料样品中多元素的准确测定。

减氮及有机替代对新疆棉田土壤氮素有效性和利用效率的影响

【目的】“连作+棉秆全量还田+高氮肥投入”是新疆绿洲棉花生产的主要技术措施之一。研究该体系下减少化肥用量对棉田土壤氮素转化和有效性的影响,以及等量有机肥替代化肥的效果,为优化施肥方案,提高氮肥利用率提供依据。【方法】于2021和2022年在新疆石河子市二连农试场开展棉花连续定位施肥试验,设置常规施氮量(CF),减施常规氮量的8%(CF-8%)、16%(CF-16%)和24%(CF-24%),在常规氮量下以有机肥替代其中8%(8%OF)、16%(16%OF)和24%(24%OF)的化肥,以及不施氮肥对照(CK),共8个处理。分析不同土层p H、电导率(EC)值、有机质、无机氮和活性有机氮含量、氮转化相关酶活性变化,计算氮肥利用率,并测定棉花产量。【结果】2021和2022年在CF处理基础上减少化肥施氮量,0—20、20—40 cm土层颗粒有机氮(PON)、轻组有机氮(LFON)含量无明显变化,而CF-16%处理可溶性有机氮(DON)和微生物量氮(MBN)占全氮(TN)的比例较CF处理分别提升14.79%和19.88%,0—20 cm土层土壤蛋白酶活性也得到显著增强。CF-24%处理0—20 cm土层微生物量氮(MBN)含量、土壤硝酸还原酶、亚硝酸还原酶活性较CF处理分别下降了10.78%、16.88%、6.25%。随着化肥施用量的减少,深层土壤中累积的NH_(4)^(+)-N与NO_(3)^(-)-N含量降低,减氮处理中CF-16%处理较CF处理的增产率最高,达6.59%。与CF处理相比,16%OF、24%OF处理显著提高了20—40 cm土层土壤p H,0—20和20—40 cm土层有机质含量分别提升了23.44%和12.99%、31.74%和20.14%,土壤EC值分别下降了7.74%和4.72%、5.64%和7.02%,能够改善棉田土壤环境。16%OF处理0—40 cm各土层颗粒有机氮和可溶性有机氮含量两年平均较CF处理分别增加了24.01%和29.15%、18.95%和55.32%,颗粒有机氮和可溶性有机氮在全氮中的占比分别增加了16.32%和32.42%,而24%OF处理的轻组有机氮含量、LFON/TN、MBN/TN、C/N在3个有机替代处理中均为最高。16%OF处理的氮肥农学利用率、氮肥偏生产力、氮肥贡献率、单铃重与产量均高于8%OF和24%OF处理,增产率达17.16%。【结论】适量减施无机氮肥能够减少土壤中无机氮的累积,提升棉花氮肥利用率和产量,以CF-16%处理表现较佳。有机肥替代部分化肥能够增加土壤中活性有机氮的含量和土壤氮转化酶活性,提高土壤供氮潜力,改善棉田土壤微环境,并通过降低20—60 cm深层土壤中的NO_(3)^(-)-N含量提升棉花氮肥利用率,增加棉花单铃重与籽棉产量,其中16%OF处理为本试验最优处理,棉花增产17.16%。

施肥对斑点叉尾鮰肠道菌群的影响

为探索斑点叉尾鮰(Ictalurus punctatus)的绿色、经济养殖模式,并为其养殖过程的施肥管理提供指导,研究了施肥对斑点叉尾鮰肠道菌群的影响。将斑点叉尾鮰分为有机肥组(Y)、无机肥组(W)与对照组(D)共3组,进行为期3个月的养殖实验。实验结束后,取出肠道内容物,通过16S rRNA扩增子测序技术检测肠道菌群。结果显示,施肥后斑点叉尾鮰肠道菌群的多样性与丰度均有所降低。在门水平上,3组的优势菌群均为厚壁菌门、变形菌门和拟杆菌门,对照组中的变形菌门、放线菌门与梭杆菌门的相对丰度显著高于施肥组(p<0.05);在属水平上,与对照组相比,施肥组中以罗姆布茨菌属(Romboutsia)和苏黎世杆菌属(Turicibacter)为优势菌属;其中,无机肥组中链球菌属(Streptococcus)相对丰度显著上升(p<0.05),对照组中的梭杆菌属(Fusobacterium)相对丰度高于施肥组(p<0.05)。经3组菌群差异性分析,无机肥组鱼体肠道中的乳酸菌含量显著增加,有机肥组中的链球菌属显著下调,降低了斑点叉尾鮰的发病机率。研究表明,在斑点叉尾鮰养殖中混合施加有机与无机肥料,能有效促进其健康生长。

多样化培肥模式调控丛枝菌根真菌促进玉米磷素吸收

利用丛枝菌根真菌(Arbuscular mycorrhizal fungi,AMF)从农田生态系统获取养分,是红壤作物吸收土壤磷(P)素的有效途径。针对我国南方红壤生物功能退化、P生物有效性低、作物产量低等问题,如何调控作物根际AMF群落,优化其与宿主的互惠共生关系,是突破红壤区作物P摄取瓶颈的关键。结合红壤旱地生态间作与有机(秸秆、猪粪、生物肥)无机肥料配施的4种多样化培肥措施,基于作物产量和红壤磷素活化水平,筛选最优培肥模式,并进一步利用扩增子高通量测序和显微观察等技术,解析红壤旱地最优培肥措施调控AMF群落组成,揭示优化的AMF群落激发宿主玉米磷素摄取机理。结果表明:相较于玉米单作配合常规化肥(Mo+NPK),花生/玉米间作结合秸秆/生物肥的有机无机配施(In+NPKSB)使红壤旱地全磷(TP)提高29.07%、有效磷(AP)提升1.35倍,且增强了玉米根内AMF群落科水平间的联系。该措施AMF定殖率是传统化肥措施的2.24倍,玉米根际酸/碱性磷酸酶(ACP/ALP)活性提高32.18%和41.66%,玉米生物量提高34.98%,产量提高67.27%。研究证实红壤旱地花生/玉米生态间作结合秸秆/生物肥有机无机配施的培肥措施可通过优化玉米根内AMF群落组成,促进土壤P活化,为在红壤旱地因地制宜推广可持续农业发展的集成应用提供理论依据。