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/（hm2.a）. The increase in SOC was only 0.31, 0.30 and 0.12 t C/（hm2.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.

Approach for improving precision of regression analysis of single-replication fertilization experiments in rice

The field experiment designs with single replication were frequently used for factorial experiments in which the numbers of field plots were limited, but the experimental error was difficult to be estimated. To study a new statistical method for improving precision of regression analysis of such experiments in rice, 84 fertilizer experiments were conducted in 15 provinces of China, including Zhejiang, Jiangsu, Anhui, Hunan, Sichuan, Heilongjiang, etc. Three factors with 14 treatments (N: 0—225kg/ha, P: 0 —112. 5kg/ha, K: 0—150kg/ha) and two replications were employed using approaching optimun design. There were 2352 (84×14×2=2352) Yield deviations (d) between the individual treatment yields and its arithmetic mean. The results indicated that:

基于“3414”试验模型的四川盆地中部水稻氮磷钾肥效应研究

本研究采用“3414”肥料效应田间试验,旨在确定四川盆地中部资中县水稻的最佳施肥量,并构建高产施肥模型。通过设置氮、磷、钾3因素,每个因素4个水平,共14个处理,每个处理重复3次。结果表明:建立的三元二次肥料效应回归方程的相关系数(R^(2))为0.976。纯氮施用量为215.28 kg/hm^(2),五氧化二磷施用量为101.40 kg/hm^(2),氧化钾施用量为104.14 kg/hm^(2),水稻最大产量为7923.56 kg/hm^(2);纯氮最佳施用量为196.83 kg/hm^(2),五氧化二磷施用量为74.81 kg/hm^(2),氧化钾施用量为102.90 kg/hm^(2),水稻最佳产量为7867.96 kg/hm^(2)。建立的肥料效应模型可在四川盆地中部类似水稻产区推广,用于水稻生产上对施肥量的预测。

Studies on the Fertilization Effect and Optimal Fertilizing Amount of Brazil Banana Based on "3414" Field Trials

Fertilizer effect model such as ternary quadratic, unary quadratic, straight line and platform model was respectively used to analyze the two-year ＂3414＂ test data collected from banana garden in Fushan Town of Hainan Province. The results showed that the optimal fertilizing amount of ternary quadratic model simulation was0.374 kg/plant of N, 0.289 kg/plant of P2O5 and 0.891 kg/plant of K2 O. According to the yield trend characteristic, the optimal fertilizing amount of unary quadratic model was 0.400kg/plant of N, 0.214 kg/plant of P2O5 and 0.901kg/plant of K2 O. Thus it can be seen that only partial indices of the optimal fertilizing amount of ternary quadratic model simulation were higher than that of unary quadratic model. Considering the results, the optimal fertilizing amount of Brazil banana was 0.374-0.400kg/plant of N, 0.214-0.289 kg/plant of P2O5 and 0.891-0.901 kg/plant of K2 O.

Effects of “3414” Fertilization Effect Test on the Yield and Economic Benefit of Sagittaria sagittifolia

[Objective] To screen the optimal fertilizer formula, and to lay foundation for the research on special fertilizer for Sagittaria sagittifolia production. [Method] Based on the ＂3414＂ fertilization design, the yield of S. sagittifolia in each treatment was determined, and the effects of N, P and K treatments on the yield and eco- nomic benefit of S. sagittifolia were investigated, obtaining the optimal fertilizer appli- cation ratio. [Result] N, P and K had relatively good effects on the yield of S. sagittifolia. Treatment of N2P2K3 showed the optimal fertilizer application ratio, with the yield of 18 397.80 kg/hm2, yield increasing rate of 104.77%, and net income in- crease of 80 317.35 Yuan/hm2. N fertilizer had the greatest impacts on the yield of S. sagittifolia, followed with K fertilizer; while P fertilizer showed the poorest impacts. [Conclusion] To achieve the highest yield of S. sagittifolia, the fertilizer application was as follows： N of 446.70 kg/hm2, P20 of 568.10 kg/hm2, K2O of 534.90 kg/hm2, when the highest yield was 18 612.75 kg/hm2. Fertilizer application for the optimal economic benefit was N of 420.60 kg/hm2, P2O5 of 70.50 kg/hm2, K2O of 492.15 kg/hm2, when the optimal yield was 18 579.00 kg/hm2.

基于3414试验设计的云南雪茄烟叶生产施肥技术研究

为明确云南省瑞丽雪茄烟区土壤合理施肥方案,采用“3414”肥料试验设计,通过熵权法和回归分析,计算了各处理对应的烟株农艺性状综合得分,探究了N、P、K对雪茄烟株长势和烟叶产量的影响,筛选出最佳施肥方案。结果表明:(1)株高对雪茄烟株农艺性状的得分所占权重最大,处理6(N_(2)P_(2)K_(2))对应的得分最高。(2)在一定范围内增加N、P、K的施用量,对雪茄烟的产量有积极作用,然而随着施肥量的增加产量又有所下降。(3)构建了N、P、K施用量对雪茄烟产量的二元二次和三元二次回归模型,最佳施肥方案为N施用量在118.7~126.9 kg/hm^(2)之间,P_(2)O_(5)施用量在75.7~81.4 kg/hm^(2)之间,K_(2)O施用量在342.1~366.5 kg/hm^(2)之间,目标产量在1816.3~1812.5 kg/hm^(2)之间。

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”试验的切花芍药氮磷钾推荐施肥量研究

针对切花芍药生长过程中盲目施肥的现状,以二年生芍药‘向天歌’为研究对象,采用“3414”试验施肥方案,结合隶属函数法,研究氮、磷、钾肥不同用量对切花芍药生长的影响,探讨切花芍药生产适宜的肥料用量。结果表明:不同施肥处理对芍药株高、茎粗、蕾径、分株数和切花数影响显著(P<0.05);氮、磷缺素区的综合隶属函数值小于无肥区,缺钾区大于无肥区,对芍药生长的影响为氮>磷>钾;N2P2K1处理的综合隶属函数值最大,为0.61,芍药植株生长最好;对各处理的综合隶属函数值和施肥量进行肥料效应函数拟合分析,一元二次、二元二次肥料效应函数方程拟合相关性均达显著水平,三元二次肥料效应方程为非典型模型,采用频率分析法计算肥料推荐量。综合分析各肥料效应函数方程的推荐用量及相应的综合隶属函数值,本试验切花芍药推荐施肥量为N 212.7 kg/hm^(2)、P_(2)O_(5)46.2 kg/hm^(2)、K_(2)O 49.9 kg/hm^(2),施肥配比为1∶0.21∶0.23,可用于本试验区切花芍药生产的施肥参考。

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。

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。

贞丰县下等肥力地小麦“3414”肥料效应试验

[目的]探索贞丰县下等肥力地小麦氮、磷、钾肥最佳施肥配比。[方法]通过小麦“3414”肥料效应田间试验,对不同施肥处理的小麦产量进行分析比较,以确定最佳施肥配比。[结果]施用不同配比的氮、磷、钾肥对小麦的农艺性状和产量有不同的影响,当施肥量为N 390 kg/hm^(2),P_(2)O_(5)750 kg/hm^(2),K_(2)O 124.5 kg/hm^(2)时,小麦的产量最高,为4 971.0 kg/hm^(2),较未施肥区增产2 131.5 kg/hm^(2)。[结论]在与该试验相同肥力条件的下等肥力地种植小麦,推荐最佳施肥量为:N 390 kg/hm^(2),P_(2)O_(5)750 kg/hm^(2),K_(2)O 124.5 kg/hm^(2)。

Effects of Long-term Fertilization on Fertility of Lateritic Red Loam Paddy

The change rules of the fertility of red soil paddy under the long-term different fertilization were investigated, and the reasonable fertilization mode to improve the fertility of red soil paddy was discussed. There were eight treatments in the experiment, which were CK （no fertilizer）, N1 （N of 60 kg/hm2）, N2 （N of 120 kg/hm2）, N1P1 （P2O5 of 30 kg/hm2）, N2P1 and N2P2 （P2O5 of 60 kg/hm2）, N2P2K1 （K2O of 45 kg/hm2） and N2P2K2 （K2O of 90 kg/hm2）. All treatments were applied with composted cow dung as the base fertilizer, and each season 50% of the straws were returned to the field. The content of organic matter, nitrogen, phosphorous and potassium in red soil paddy was observed continuously for ten years and their correlation was also analyzed. Under cow manure and straw return to field, organic matter content of different treatments was positively correlated to year. After ten years, organic matter content of surface soil rose by 2.5 g/kg averagely with an annual increase of 0.25 g/kg. Total nitrogen content and organic matter content of different treatments presented similar variation trend. Total nitrogen content rose by 0.35 g/kg averagely with an annual increase of 0.035 g/kg. Among all the treatments, N2P2K1 and N2P2K2 showed the biggest increase, which went up by 0.052 and 0.48 g/kg, respectively. Phosphorous-free treatments （CK, N1, N2） had steady phosphorous content with irregular changes of different years. Total phosphorous content of phosphorous treatments increased year by year. Total phosphorous content of N1P1 and N2P1 rose by 0.008 g/kg every year. The increment range of total phosphorous content of N2P2, N2P2K1 and N2P2K2 was 0.012 -0.013 g/kg annually. Available phosphorous content varied vastly among different treatments. Available phosphorous content of organic fertilizer treatments basically remained stable with irregular changes of different years. Available phosphorous content of organic fertilizer with phosphate fertilizer treatments rose year by year. Available phosphorous content of N1P1 and N2P1 rose approximately by 0.8 mg/kg. Available phosphorous content of N2P2, N2P2K1 and N2P2K2 rose approximately by 1.4 -1.6 mg/kg annually. Potassium fertilizer amount greatly affected total potassium content. Total potassium content of no-potassium treatments （CK, N1, N2, N1P1, N2P1 and N2P2） remained the same. Total potassium content of N2P2K markedly increased year by year, which was 0.014 g/kg annually. Rapid available potassium content of no-potassium treatments （CK, N1, N2, N1P1, N2P1 and N2P2） showed a decreasing trend. With phosphate fertilizer, rapid available potassium content of N2P2K1 and N2P2K2 remained the same or increased year by year. The change trend of slow available potassium content and rapid available potassium content resembled. Rational allocation of organic fertilizer, nitrogenous fertilizer, phosphate fertilizer and potassium fertilizer can significantly improve soil fertility and economic benefits. Balanced fertilization is an effective measure for soil fertility improvement as it＇s shown that nutrients of surface soil accumulate annually.

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。

Establishment and Application of Fertilization Model for Wheat Interplanted with Cotton in Jianghan Plain

3414 field experiment （including three nutrient elements at four gradient levels, a total of 14 unrepeated incomplete treatments） was designed to study the fertilization measures for wheat interplanted with cotton in Qianjiang City, Hubei Province. Fertilizer model for wheat interplanted with cotton in Jianghan Plain was finally established, based on which the soil nutrient indices in wheat-cotton inter- planting field were screened; and optimal nitrogen, phosphorus and potassium appli- cation for wheat was put forward as 130-210 kg/hm2 N, 40-70 kg/hm2 P2O5 and 40-60 kg/hm2 K2O.

基于“3414”试验的红心甘薯新品种‘莆薯17’优化施肥技术研究

为高产高效栽培红心甘薯新品种‘莆薯17’,采用“3414”肥料效应试验方案,研究氮磷钾配施对‘莆薯17’鲜薯产量的影响以及肥料效应。结果表明,影响‘莆薯17’产量的主要因素是钾肥,氮肥次之,磷肥最小。氮磷钾之间互作效应均可影响‘莆薯17’产量。氮磷钾施用量与‘莆薯17’产量的效应函数寻优结果表明,鲜薯获得最高产量(55646.98 kg/hm^(2))时的最大施肥量分别为氮肥206.88 kg/hm^(2)、磷肥100.37 kg/hm^(2)、钾肥252.86 kg/hm^(2),氮磷钾配比为1:0.49:1.22。氮肥最佳施肥量为199.42 kg/hm^(2),磷肥最佳施肥量为95.40 kg/hm^(2),钾肥最佳施肥量为238.50 kg/hm^(2),对应的最佳鲜薯产量为55574.07 kg/hm^(2),氮磷钾配比为1:0.48:1.2。

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.

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 NO3- residue and NO3- movement downward in soil profiles; amending phosphate fertilizer or organic manure with nitrogen fertilizer together could significantly improve the status of NO3- 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 NO3- leaching in Northern China. (3) Precipitation influenced the amounts and depth of soil NO3- leaching: NO3- 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.

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 rnm 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.

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

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