Crop yields and soil organic carbon dynamics in a long-term fertilization experiment in an extremely arid region of northern Xinjiang, China

A long-term fertilization experiment was set up in northern Xinjiang, China to evaluate the dynamics of crop production and soil organic carbon(SOC) from 1990 to 2012 with seven fertilization treatments. The seven treatments included an unfertilized control(CK) and six different combinations of phosphorus(P), potassium(K), nitrogen(N), straw(S) and animal manure(M). The balanced fertilization treatments had significantly(P<0.05) higher average yields than the unbalanced ones. The treatment with 2/3 N from potassium sulfate(NPK) and 1/3 N from farmyard manure(NPKM) had a higher average yield than the other treatments. The average yields(over the 23 years) in the treatments of NPK, and urea, calcium superphosphate(NP) did not differ significantly(P>0.05) but were higher than that in the treatment with urea and potassium sulfate(NK; P<0.05). The results also show that the highest increases in SOC(P<0.05) occurred in NPKM with a potential increase of 1.2 t C/(hm^2·a). The increase in SOC was only 0.31, 0.30 and 0.12 t C/(hm^2·a) for NPKS(9/10 N from NPK and 1/10 N from straw), NPK and NP, respectively; and the SOC in the NP, NK and CK treatments were approaching equilibrium and so did not rise or fall significantly over the 23-year experiment. A complete NPK plus manure fertilization program is recommended for this extremely arid region to maximize both yields and carbon sequestration.

Steel Slag as an Iron Fertilizer for Corn Growth and Soil Improvement in a Pot Experiment

The feasibility of steel slag used as an iron fertilizer was studied in a pot experiment with corn. Slag alone or acidified slag was added to two Fe-deficient calcareous soils at different rates. Results showed that moderate rates (10 and 20 g kg-1) of slag or acidified slag substantially increased corn dry matter yield and Fe uptake. Application of steel slag increased the residual concentration of ammonium bicarbonate-diethylenetriamine pentaacetic acid (AB-DTPA) extractable Fe in the soils. The increase of extractable Fe was usually proportional to the application rate, and enhanced by the acidification of slag. Steel slag appeared to be a promising and inexpensive source of Fe to alleviate crop Fe chlorosis in Fe-deficient calcareous soils.

基于“3414”肥效试验建立BP神经网络寻优的新模型初探

针对上海市崇明滧东地区传统施肥方式不能满足水稻需肥规律的问题,以水稻“3414”肥效试验结果为数据来源,以N、P_(2)O_(5)、K_(2)O施用量为优化目标,建立3-7-1拓扑结构BP神经网络模型,通过遗传算法得到最优产量下的最优施肥配比。预测结果表明:当地较优的施肥配比是N、P_(2)O_(5)、K_(2)O的施用量分别为24.94、0.87、4.27 kg/亩(1亩=667 m^(2)),预计最高产量为531.5 kg/亩。通过验证试验,在较优的施肥配比条件下,水稻的实际产量为548.7 kg/亩,验证了BP神经网络模型预测结果的准确性。

甘南高寒阴湿区宽幅匀播青稞“3414”肥效试验

为了将宽幅匀播技术与“3414”肥效试验相结合,应用于甘南高寒阴湿区青稞种植与示范推广中,推动该地区青稞种植产业发展。采用“3414”最优回归设计,以青稞甘青9号为指示品种,在宽幅匀播条件下研究了“3414”肥效试验对青稞生长及产量的影响,并建立了青稞产量与氮、磷、钾施量之间的肥效回归方程,以提高肥效,促进甘南高寒阴湿区青稞生产优质高产。结果表明,宽幅匀播条件下,甘青9号最佳产量为6640.32kg/hm^(2)时,施肥量为N36.34kg/hm^(2)、P_(2)O_(5)55.86kg/hm^(2)、K_(2)O7.09kg/hm^(2);最大产量为6834.09kg/hm^(2)时,施肥量为N80.66 kg/hm^(2)P_(2)O_(5)62.31kg/hm^(2)、K_(2)O16.58kg/hm。肥效回归方程中施肥量与青稞产量拟合度显著,可应用于大田生产。

剑麻“3414”肥料效应研究

采用“3414”肥料效应试验方案,研究了剑麻氮磷钾肥推荐用量及养分吸收状况,为剑麻科学精准施肥提供参考。结果表明,N_(2)P_(2)K_(2)处理收获叶片数和鲜叶产量均最高,其N、P_(2)O_(5)、K_(2)O施用量分别为163.9、71.1、310.1 kg/hm^(2),比例为1.0∶0.4∶1.9。试验区土壤N、P含量均处于中等水平,土壤K含量处于低水平;叶片N含量偏高,P含量适宜,而K含量偏低,说明钾素是限制该区域剑麻产量的主要因素。随着叶片收获,不同处理平均N、P、K带走量分别为273.4、29.0、292.8 kg/hm^(2)。本试验条件下,推荐氮磷钾肥用量分别为N 126.2~141.0、P_(2)O_(5)59.0~65.8、K_(2)O 252.7~280.6 kg/hm^(2),折尿素274.3~306.5 kg/hm^(2),过磷酸钙368.8~411.3 kg/hm^(2),氯化钾421.1~467.7 kg/hm^(2),平均分别为N 133.6 kg/hm^(2)、P_(2)O_(5)62.4 kg/hm^(2)、K_(2)O 266.7 kg/hm^(2),N∶P_(2)O_(5)∶K_(2)O=1.0∶0.5∶2.0。

Effects of long-term fertilization on soil gross N transformation rates and their implications

Application of fertilizer has been found to significantly affect soil N cycling. However, a comprehensive understanding of the effects of long-term fertilization on soil gross N transformation rates is still lacking. We compiled data of observations from 10 long-term fertilization experiments and conducted a meta-analysis of the effects of long-term fertilization on soil gross N transformation rates. The results showed that if chemical fertilizers of N, P and K were applied in balance, soil p H decreased very slightly. There was a significantly positive effect of long-term fertilization, either chemical or organic fertilizers or their combinations, on gross N mineralization rate compared to the control treatment(the mean effect size ranged from 1.21 to 1.25 at 95% confidence intervals(CI) with a mean of 1.23), mainly due to the increasing soil total N content. The long-term application of organic fertilizer alone and combining organic and chemical fertilizer could increase the mineralization-immobilization turnover, thus enhance available N for plant while reduce N losses potential compared to the control treatment. However, long-term chemical fertilizer application did not significantly affect the gross NH4+ immobilization rate, but accelerated gross nitrification rate(1.19; 95% CI: 1.08 to 1.31). Thus, long-term chemical fertilizer alone would probably induce higher N losses potential through NO3– leaching and runoff than organic fertilizer application compared to the control treatment. Therefore, in the view of the effects of long-term fertilization on gross N transformation rates, it also supports that organic fertilizer alone or combination of organic and chemical fertilizer could not only improve crop yield, but also increase soil fertility and reduce the N losses potential.

Effect of long-term fertilization on soil nitrate distribution

A thirteen years long term field fertilizer experiment was conducted to monitor the effect of different fertilization on soil nitrate distribution. The results showed: (1) Applying relative excessive N fertilizer could result large quantities of NO - 3 residue and NO - 3 movement downward in soil profiles; amending phosphate fertilizer or organic manure with nitrogen fertilizer together could significantly improve the status of NO - 3 leaching downward due to the balanced uptake of nutrients by crops. (2) Appropriate amounts of nitrogen fertilizer which was equal or smaller than the optimal fertilization rate could not result in more NO - 3 leaching in Northern China. (3) Precipitation influenced the amounts and depth of soil NO\+-\-3 leaching: NO - 3 could move to 80 cm depth or below at autumn or at the next spring when rainfall was higher during the rainy season through July to September in North China.

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, includingCalcaric Purpli-Orthic Primosols (purple sand-shale parent material), Dystric Turbi-Anthric Primosols (quaternary red clayparent material) and Typic Udi-Sandic Primosols (granite parent material) were studied under a long-term experiment byusing crop straw and inorganic fertilizers at the Hunan Red Soil Experiment Station of Chinese Academy of AgriculturalSciences. The results showed that the contents of OM, N, P and K in the three selected soils increased after 23 yearsapplication of crop straw and inorganic fertilizers, but the contents increased much less when crop straw or inorganicfertilizers was applied alone. The nutrient contents in the three soils developed from granite changed more remarkablythan 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, alkali-hydrolyzable N and available K, the positive correlation between application of organic fertilizers and increase of OM insoil did not always happened, it provided evidence for the relation between appropriate C/N ratio and accumulation of OMin soil. The increase of nutrient content was influenced by the soil properties. By comparing the contents of nutrient in0-20 cm depth in the three different soils, it was concluded that the most increases of OM, alkali-hydrolyzable N, andavailable 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 applicationof inorganic fertilizer and crop straw was important to improve the soil fertility for all of three selected soils. The strawreturn to the field had played a significant role for enhancement of the soil quality in the study areas. The application ofinorganic fertilizer combined with the straw return to the fields could remarkably improve the soil fertility.

Effects of Long-Term Fertilization on Distribution of Organic Matters and Nitrogen in Cinnamon Soil Macro-Aggregates

Soil samples collected from a 25-year long-term fertilizer experiment carried out on the Earth-cumulic-Orthic Anthrosols in semi-humid farmland ecological system, were used to study the distribution of soil organic matters, total nitrogen, nitrate nitrogen, and ammoniate nitrogen in different grades of soil macro-aggregates in order to study the effects of long-term application of organic manures in combination with chemical fertilizers. It is showed that the percentage of mass of the soil macro-aggregates with long-term application of fertilizers with sizes of 5-2 mm is increased compared with that of the samples with no fertilizer. It is easier to form lager size soil macro-aggregates by the long-term application of organic manures in combination with chemical fertilizers. The contents of organic matters, total nitrogen and nitrate nitrogen are all higher after treatments with different combinations of fertilizers, while there is a little effect on the contents of ammoniate nitrogen. The contents of organic matters, total nitrogen in the grades of soil macro-aggregates from the plough layers of the treated farmland exhibited significant difference. Moreover, the contents of organic matters and total nitrogen in the soil macro-aggregates with the size of 1-0.25 mm is the highest in all treated soil samples. The contents of nitrate nitrogen in soil macro-aggregates increased with the increasing of soil macro-aggregate size except those applied with chemical fertilizer and lower amount of corn stover. The results of correlation analysis revealed that there exists a significantly positive correlation between the percentage of mass of soil macro-aggregates with the size of 5-2 mm and the contents of organic matters, total nitrogen and nitrate nitrogen in the soil samples. However, the correlation between the percentage of mass of soil macro-aggregates with the size of 1-0.25 mm and the contents of total nitrogen and nitrate nitrogen is significantly negative.The study showed that the highest contributing rates of macro-aggregates fractions to soil fertility is from the soil macro-aggregates fraction with the size of 1-0.25 mm in most of the cases.

雪茄烟品种楚雪26号“3414”肥效试验

采用“3414”试验设计,研究氮磷钾肥料不同用量处理对雪茄烟品种楚雪26号产量和养分吸收利用的影响。结果表明:与不施肥处理相比,各施肥处理显著提高雪茄烟叶的产量,增产效果顺序为氮肥>钾肥>磷肥;氮磷钾肥料合理施用可以优化烟叶等级结构,增加茄衣和茄套的产量,提高产值;通过一元二次回归拟合发现,烟叶最大产量时的施氮量为138.75 kg/hm^(2)、施磷量为71.85 kg/hm^(2)、施钾量为361.65 kg/hm^(2)。综合考虑产量、产值、养分吸收等指标,氮肥推荐施用量为130~140 kg/hm^(2)、磷肥推荐施用量为60~70 kg/hm^(2)、钾肥推荐施用量为340~360 kg/hm^(2)。

Effect of Fertilization on the Impact of Weather Changes on Crop Yield

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基于“3414”试验模型的大蒜氮磷钾肥效应研究

为探索大蒜生产对N、P、K的有效利用率,建立高效的大蒜施肥模型,完善大蒜施肥技术体系,指导大蒜大田生产精准施肥,以四川早熟蒜为试验对象,采用“3414”肥料效应田间试验,摸清四川早熟蒜在弥渡县生产过程中的农艺性状、产量、肥料效应。结果表明,在该试验条件下,当667 m^(2)施N 29.64 kg、P_(2)O_(5)9.6 kg、K_(2)O 25.27 kg,可得到最佳蒜薹产量869.18 kg;当667 m^(2)施N 37.45 kg、P_(2)O_(5)10.27 kg、K_(2)O 28.78 kg,可得到最佳蒜头产量1678.48 kg,其中单位养分对蒜薹的平均增产量以氮肥最高(11.02 kg/kg),钾肥次之(0.85 kg/kg),磷肥最低(0.02 kg/kg);单位养分对蒜头的平均增产量以氮肥最高(19.26 kg/kg),钾肥次之(0.11 kg/kg),磷肥最低(-0.6 kg/kg),其中磷肥为负效应。

乌兰县藜麦“3414”田间肥效试验

为确定乌兰县藜麦种植的最佳施肥模式,于2021年进行了藜麦“3414”田间肥效试验。结果表明:氮磷、钾肥配合施用可以显著提高藜麦产量;藜麦对氮、磷、钾肥的依存度分别为67.27%、43.64%、30.91%,氮肥和磷肥对藜麦产量的影响较大,钾肥次之。

三亚市水稻氮磷钾肥利用率田间试验探析

海南省三亚市是中国南繁育种基地之一,水稻为全市的主要粮食作物,在生产过程中合理施用肥料以提高产量极其重要。本试验通过田间水稻种植试验和实验室检测及数据分析,探讨氮肥、磷肥、钾肥不同配施水平对水稻产量及肥料利用率的影响。结果表明,测土配方施肥的水稻产量最高,处理1的理论产量为558.04 kg/667m^(2),氮肥利用率为41.37%、磷肥利用率为22.73%、钾肥利用率为45.84%。本试验旨在为三亚市水稻种植中推广测土配方施肥技术提供数据支撑和参考。

土壤肥料学实验课操作视频开发探索与实践

土壤肥料学实验是农科类核心专业基础课。本着让学生准确规范地掌握实验操作技能的同时,丰富和完善实验教学资源从而提高实验课的教学效果,为该专业今后的教学、科研和农业技术服务提供高品质的资源保障。作者根据多年课堂实践,总结学生在实验课中常见的错误操作,深入了解学生和实验教师需求,录制开发土壤肥料学实验基本操作视频。视频录制既考虑实验流程的完整性和时效性,又强化实验中关键环节的独立性、规范性和广适性。视频资源的开发和网络推广有效弥补传统课堂模式的不足,以其演示的直观化和内容可再现等特点,既方便学生课前预习,提高学生实验操作技能,又便于学生课后随时复习,巩固实验相关知识,对提高实验教学效果有明显的推动作用。

3414"肥料试验模型拟合的探讨

以UNDP95-98年在河北唐山进行的27个"3414"冬小麦试验为例,研究了三元二次施肥模型与一元施肥模型对"3414"肥料试验结果的拟合情况。结果表明,三元二次施肥模型进行拟合试验成功率仅为56%,而采用一元施肥模型可以对全部试验进行数据处理。在同一试验中,与一元施肥模型相比,采用三元二次施肥模型计算的推荐施肥量偏高;根据一元施肥模型拟合计算分别有15%、44%、67%的点不需要施用N、P、K肥,而采用三元二次施肥模型则无法获得这一信息。因此,在"3414"试验中,一元施肥模型是三元二次施肥模型拟合的一种很好补充和优化手段。

应用“3414”肥料试验模型求解春玉米施肥参数的研究

利用现代肥料二次回归"3414"设计,对春玉米施肥参数进行了研究。结果表明:通过三元二次肥料效应函数获得的最高产量在各类型函数中最低,投入的肥料价值也最低,获得的产投比较高;通过一元二次肥料效应函数获得的最高产量最高,其中K处理一元二次肥料效应方程获得的最高产量和产投比最高。各类型函数所获得的最佳经济产量表现为:一元函数>二元函数>三元函数,但三元二次肥料效应函数所获得的产投比远远高于其他函数,可用于推荐施肥。通过三元二次肥料效应函数获得的春玉米推荐施肥指标为:N162.8kg/hm2,P2O5112.7kg/hm2,K2O149.7kg/hm2,需要投入的肥料成本为1776元/hm2,可获得最佳经济产量13241kg/hm2,产投比高达7.45。

免耕水稻在“3414”试验方案中氮磷钾配施的肥料效应研究

在免耕抛秧种植模式下进行"3414"肥料效应试验,通过建立氮、磷、钾施肥量与产量的回归模型,探索当地水稻的最佳施肥量。结果表明,氮磷钾施用量均为中等水平时,产量和经济效益达到最佳;各类型函数所获得的最佳经济产量表现为一元函数>二元函数>三元函数。结合一元、二元、三元肥料效应函数及实际生产而获得的推荐施肥指标:最高产量施肥量为每公顷施N 197.70 kg,P2O573.05 kg,K2O 180.00 kg;最佳产量施肥量为每公顷施N 194.10 kg,P2O5 65.55 kg,K2O 170.10 kg。

湛江市甘蔗“3414”肥料效应试验

利用肥料二次回归"3414"设计,对湛江市甘蔗施氮、磷、钾肥料参数进行研究。结果表明:全肥区比缺氮区、缺磷区及缺钾区分别增产6.33%、8.62%及2.44%,其中以磷肥的增产率为最高。通过三元二次施肥模型计算,得出N、P2O5和K2O的最佳施用量分别为171.3、432.0、0 kg/hm2,收益是40 367.92元/hm2。通过肥料"3414"试验,能实现主要养分平衡供应,满足甘蔗高产高糖生产需要,达到提高肥料利用率及高产的目的。

药用金荞麦“3414”施肥效应研究

目的:研究重庆渝西紫色土N、P、K不同施用量和不同组合方式对金荞麦根茎产量的影响,探索该类型土壤下的施肥优化方案。方法:采用"3414"施肥设计方案设计实验,在Excel 2003、SPSS 13.0、Matlab 7.0和Word2003下对数据处理,根据双聚原矢车菊苷元含量评定其品质。结果:不同施肥组合,肥料的有效转化率有差异,其中有效转化率最高组合为N3P2K2,为97.09%,最低组合为N0P2K2,为4.32%;除空白组外,N0P2K2组产量最低为186 kg/667 m2,N2水平15 kg/667 m2,另外两种肥料组合在高、中、低三个水平上差异不大;一元、二元、三元函数拟合效果都较为理想,其中R2值排前三的函数是N、K效应函数、N效应函数和N、P、K三效应函数;不施肥组双聚原矢车菊苷元含量最高为8.67%,高N、高K组其含量降低,但所有的含量均高于7.14%。结论:不同施肥组合,对单一肥料的转化率有一定影响;该类土壤N肥施用量是决定其产量的关键肥料,故应偏重于氮肥施用;可以采用N、K效应函数、N效应函数和N、P、K三效应函数任意一种作为指导该类型土壤的施肥依据;施肥后各组药效成分含量虽然有差异,但不降低金荞麦品质。