Effect of Long-Term Application of K Fertilizer and Wheat Straw to Soil on Crop Yield and Soil K Under Different Planting Systems

Effect of application of K fertilizer and wheat straw to soil on crop yield and status of soil K in the plough layer under different planting systems was studied. The experiments on long-term application of K fertilizer and wheat straw to soil in Hebei fluvo aquic soil and Shanxi brown soil in northern China were begun in 1992. The results showed that K fertilizer and straw could improve the yields of wheat and maize with the order of NPK ＋ St 〉 NPK 〉 NP ＋ St 〉 NP, and treatment of K fertilizer made a significant difference to NP, and the efficiency of K fertilizer in maize was higher than in wheat under rotation system of Hebei. In contrast with Shanxi, the wastage of soil potassium was a more serious issue in the rotation system in Hebei, only treatment of NPK ＋ St showed a surplus of potassium and the others showed a wane. K fertilizer and straw could improve the content of water-soluble K, nonspecifically adsorbed K, non-exchangeable K, mineral K, and total K in contrast to NP; however, K fertilizer and straw reduce the proportion of mineral K and improve proportion of other forms of potassium in the two locating sites. Compared with the beginning of orientation, temporal variability character of soil K content and proportion showed a difference between the two soil types; furthermore, there was a decrease in the content of mineral K and total K simultaneously in the two locating sites. As a whole, the effect of K fertilizer applied to soil directly excelled to wheat straw to soil. Wheat straw to soil was an effective measure to complement potassium to increase crop yield and retard the decrease of soil K.     

长期施肥对绿洲农田土壤生产力及土壤硝态氮积累的影响

 在甘肃河西绿洲灌漠土上进行的长期定位试验表明，连续20年不施用任何肥料，导致农田土壤生产能力严重衰退。2001年不施肥的小麦产量仅是试验开始时（1982年）的25.7%，2000年的玉米产量为1984年的28.2%。肥料是影响农田土壤生产力的重要因素，不同肥料的影响程度依次是：氮肥＞有机肥＞磷肥＞钾肥，其平均增产率分别为36.5%、27.3%、24.7%和2.9%。随着试验年限的延长，不施任何肥料的对照产量持续降低，故氮肥的增产效果增加；磷肥增产效果比较平稳；钾肥在试验开始后最初6年（1982～1987年）无显著增产效应，中期具有一定的增产作用（1988～1992年），后期8年（1993～2001年）显著增产。施用有机肥的增产作用随着试验延续呈逐步增加的趋势，表明长期施用有机肥具有明显的残效叠加效应。不同施肥处理对土壤中NO-3-N的积累与分布有显著的影响。施用化肥的处理（NP和NPK）导致NO3--N在土壤剖面中大量积累，尤其是在20～140 cm土层。化肥与有机肥配合施用(MNP 和 MNPK) NO3--N在土壤剖面中的积累显著低于化肥处理。长期连续施用化肥和有机肥均导致土壤剖面中硝态氮的积累；与化肥相比，有机肥导致更深土壤剖面（140～180 cm）中硝态氮的积累，因此，长期有机无机肥配合施用可显著增加绿洲农田土壤生产力，维持和提高土壤质量，但从持续农业发展及保护生态环境等方面考虑，应适当降低施肥量。     

氮肥及其与秸秆配施在不同肥力土壤的固持及供应

【目的】在有机物料和无机氮肥的配施条件下,研究氮素在土壤中的固持与释放过程,以期达到土壤供氮与作物需氮相一致的目的。【方法】以长期定位试验不同施肥处理土壤（不施肥,NF;施用氮磷钾化肥,NPK;厩肥与化肥配施,MNPK）为研究对象,采用盆栽试验研究化学氮肥及其与秸秆配施在不同肥力土壤中的固持与供应。【结果】与未施氮肥（对照）相比,单施尿素对NF处理土壤小麦籽粒产量无显著影响,而显著提高了NPK和MNPK处理土壤小麦籽粒产量;MNPK处理土壤氮肥利用率（67%）显著高于NPK（56%）和NF（19%）处理土壤。与施用氮肥处理相比,秸秆与尿素配施显著降低了小麦产量和氮素利用率,但MNPK处理土壤小麦产量及氮肥利用率（11%）仍显著高于NPK处理（7%）;秸秆与尿素配施降低了当季小麦对施入氮素的吸收利用,小麦收获时不同施肥处理土壤有79%-88%施入的氮素未被吸收利用。【结论】有机肥与化肥长期配施在协调土壤氮素供应,提高作物产量及氮肥利用率方面具有突出作用。     

Effect of Long-Term Fertilization on Soil Productivity and Nitrate Accumulation in Gansu Oasis

A long-term （1982-2001） field experiment was conducted in a calcareous soil under wheat （Triticum aestivum L.）-wheat （Triticum aestivum L.）-maize （Zea mays L.） rotation system at Zhangye, Gansu Province, China to determine the effects of long-term fertilization on crop yield, nutrients interactions, content and accumulation of nitrate-N in soil profiles. Twenty- four plots in a split-plot factorial with a combination of eight treatments （from nitrogen （N）, phosphorus （P）, potassium （K） and farmyard manure （M） applications） and 3 replications were selected. Main treatments were M and without M, and the sub-treatments were no-fertilizer （CK）, N, NP and NPK. When P and K fertilizers were part of treatments, their ratio to N was 1N：0.22P：0.42K. All M, P and K fertilizers were applied as the basal dressing. The grain yield was harvested each experimental period and straw yield for the period from 1988 to 1997. After crop harvest in 2000, the soil was sampled from the 0-20, 20-60, 60-100, 100-140 and 140-180 cm depths to determine NO3^--N content. Maize yield of CK in 2000 was only 28.2% of that in 1984, and wheat in 2001 was 25.7% of that observed in 1982. Average impact of fertilizers on grain yield decreased in the order of N 〉 M 〉 P 〉 K. Yield response to N and P fertilizers increased with progress of the experiment. The impact of K fertilizer showed no increase in grain yield during the initial 6 years （1982-1987）, moderate increase in the next 5 years （1988-1992）, and considerable increase in the last 9 years （1993-2001）. The straw yield trend was similar to grain yield. Accumulation and distribution of NO3^--N in soil was significantly affected by annual fertilizations. Mineral fertilizers （NP and NPK） led to NO3^- -N accumulation in most subsoil layers, with major impact in the 20-140 cm depth. The combination of mineral fertilizers and farmyard manure （MNP and MNPK） reduced soil NO3^--N accumulation in comparison to mineral fertilizers, It can be argued that long-term fertilization significantly enhanced grain and straw yield in this rotation scheme. The findings of this research suggest that it is important to balance application of mineral fertilizers and farmyard manure in order to protect soil and underground water from potential NO3^--N pollution while sustaining high productivity in the oasis agro-ecosystem.     

周年氮磷钾配施模式对砂姜黑土麦玉轮作体系籽粒产量和养分利用效率的影响

【目的】探讨周年不同氮磷钾配施对砂姜黑土麦玉轮作体系产量及养分利用效率的影响,明确适宜豫东南砂姜黑土麦玉一体化种植的氮磷钾配施模式。【方法】于2012—2014年连续两年在河南省周口市商水县典型砂姜黑土区设置氮磷钾不同配施大田定位试验,研究磷钾肥总用量不变、2种氮用量投入水平下麦玉两季磷钾配施模式对冬小麦-夏玉米轮作种植体系氮、磷、钾养分吸收利用及产量的调控效应。其中,氮肥设全年用量360.00kg·hm~(-2)和540.00 kg·hm~(-2)两个梯度,磷钾肥总量不变,设计4种配施方式,即麦季全磷玉米全钾(磷肥和钾肥分别全部施用于小麦季和玉米季)、麦季全磷玉米重钾(磷肥全部施用于小麦季,钾肥按麦玉两季42﹕58的比例分配)、麦季重磷玉米全钾(磷肥按麦玉两季64﹕36的比例分配,钾肥全部施用于玉米季)、麦季重磷玉米重钾(磷肥按麦玉两季64﹕36的比例分配,钾肥按麦玉两季42﹕58的比例分配)。【结果】高氮水平下麦玉两季磷钾肥分施能促进作物产量三要素的协调发展,显著提高冬小麦的穗数和夏玉米的穗长与行粒数,且两年度单季作物和全年籽粒产量均以麦季重磷且玉米季重钾P8处理最高,周年产量分别达21 274.2 kg·hm~(-2)和20 219.1 kg·hm~(-2)。砂姜黑土区冬小麦和夏玉米地上部养分含量大小均表现为氮钾磷。与低氮水平相比,高氮水平有利于提高植株地上部总氮、磷、钾的含量,然而氮素的偏生产力(NPFP)、吸收效率(NUPE)、利用效率(NUE)有所降低。磷钾肥分施不仅能促进冬小麦和夏玉米对氮素的吸收,还可有效防止元素的流失,提高作物对磷素和氮素的吸收和利用,显著提高磷钾两类元素的偏生产力(PFP)、吸收效率(UPE)。而磷钾全施在麦玉某一季作物上,由于磷肥易固定、钾肥易流失的原因,造成肥料后效减小,下茬作物因养分供给不平衡而影响作物对氮磷钾的吸收利用,致使产量降低。低氮水平下麦季重磷、玉米季重钾P4处理的氮磷钾养分利用较其他处理表现较优;高氮水平下麦季重磷、玉米季重钾P8处理的单季和周年氮素偏生产力及吸收效率均显著高于其他处理。【结论】综合考虑养分利用效率和籽粒产量,在本试验条件下,麦季重磷、玉米季重钾配施模式有利于养分效率和产量的同步提高,可作为豫东南砂姜黑土及相似生态类型区冬小麦-夏玉米轮作种植高产高效施肥的优选模式。     

Long-term effect of fertilizer application on rice yield,potassium uptake in plants,and potassium balance in double rice cropping system

A 27 years field experiment was conducted on a Fe-Accumli Stagnic Anthrosol to evaluate the effects of long-term application of fertilizer, pig manure (PM), and rice straw (RS) on rice yield, uptake, and usage efficiency of potassium, soil K pools, and the nonexchangeable K release under the double rice cropping system in South Central China. Common cropping pattern in the study was early rice-late rice-fallow (winter). The field treatments included CK (no fertilizer applied), NP, NK, NPK, and NK + PM, NP + RS, NPK + RS. The pig manure and rice straw was applied in both the early rice and late rice cropping season. The ranking order of 27 years average annual grain yield were the CK<NK<NP<NK + PM<NP + RS<NPK<NPK + RS treatments. The negative yield change trends were observed in the CK and NP and NK treatments of unbalanced nutrient application in the case of omitted-K and P-omitted. The positive yield change trends were observed in balanced applications of NPK and combined application of fertilizer (NPK) with pig manure (NK + PM) or rice straw (NP + RS and NPK + RS). The application of K fertilizer (NPK) increased grain yield by 56.7 kg·hm⁻²·a⁻¹ over that obtained with no K application (NP). The combined application of pig manure with fertilizer (NK + PM) increased by 82.2 kg·hm⁻² per year compared with fertilizer application alone (NK). The combined application of rice straw with fertilizer (NP + RS and NPK + RS) increased on the average of 34.4 kg·hm⁻² per year compared with fertilizer application alone (NP and NPK). In all fertilizer, pig manure and rice straw combinations, K uptake change trends in rice plants of the early rice was positive except for CK and NP treatments. The results showed that the total removal of K by the rice plants exceeded the amounts of total K applied to the soil in all treatments, which showed a negative K balance. This ranged from 106.3 kg·hm⁻²·a⁻¹ in CK treatment to 289.6 kg·hm⁻²·a⁻¹ in the NPK + RS treatment. Continuous annual application of 199.2 K kg·hm⁻² to rice resulted in an accumulation (58 kg·hm⁻²) of exchangeable K (1 mol NH₄OAc extractable K) in 0–45 cm soil depth over the study period, despite the higher average annual uptake of K by the system (225.7 kg·hm⁻²). However, nonexchangeable K increased substantially from 1090 kg·hm⁻² to 1113 kg·hm⁻² and 1140 kg·hm⁻² in the 0–45 cm soil layer in NPK + RS and NPK treatments after 27 years of the continuous double rice cropping system, respectively. Thus, long-term rational application of K fertilizer may increase sustainable K fertility of the continuous double rice cropped system.     

河南省不同类型小麦养分吸收分配规律

依据大田长期施肥试验(1991-2008年)中9个中筋和强筋小麦品种对N、P、K的吸收和分配变化规律,探索小麦品种及筋型对养分的吸收差异,为小麦专用肥研发与合理施肥提供指导.结果表明,以豫麦13号为代表的中筋小麦,每生产100 kg小麦籽粒需要N、P、K分别为2.06kg、0.44kg和1.84 kg,需要N∶P∶K比...     

长期施用化肥和稻草对红壤水稻土肥力和生产力持续性的影响

 【目的】研究长期施用氮（N）、磷（P）、钾（K）化肥和稻草（RS）对中国亚热带地区红壤水稻土肥力变化的趋势和水稻生产力可持续性的影响。【方法】利用1981年建立在湖南省望城县黄金乡第四纪红土红壤发育的水稻土（分类为普通简育水耕人为土）上的定位试验田,对氮、磷和钾化肥及其与稻草长期配合施用的5个处理的土壤肥力和生产力可持续性进行了评价。【结果】氮、磷和钾化肥与稻草长期配合施用能维持和提高红壤水稻土的生产力和土壤肥力;水稻获得了持续高产,土壤有机质、全氮、全磷、可矿化氮量均增加,速效磷和速效氮比试前土壤增加。长期施用氮、磷肥而不施钾肥的NP处理水稻产量、土壤氮、钾逐年降低,稻田系统生产力的可持续性和土壤肥力难以维持。稻草还田对水稻具有显著的增产作用,27年54季的稻草还田配合化肥处理的平均水稻产量比仅施化肥的NP和NPK处理分别增产12.2%和6.7%,稻草的增产作用还随着稻草还田时间的延长而逐年提高。【结论】稻草还田携入的钾与化学钾肥具有相同的营养功能,稻草可替代部分化学钾肥。     

不同种植制度下长期施钾与秸秆还田对作物产量和土壤钾素的影响

【目的】研究施钾和秸秆还田对华北地区不同种植制度下作物产量和耕层土壤钾素状况的影响。【方法】在华北平原的河北潮土和山西褐土上进行连续13年的施钾和秸秆还田试验。【结果】施钾和秸秆还田能增加小麦和玉米产量，处理之间表现为：NPK+St＞NPK＞NP+St>NP，施钾处理的作物产量与NP处理的产量差异显著，轮作制度下玉米的施钾效应高于小麦。与山西单作制度相比，河北轮作制度下的土壤钾素损耗严重，除NPK+St处理外土壤钾素均表现亏缺。秸秆还田和施用钾肥较NP处理可不同程度提高河北潮土和山西褐土耕层土的水溶性钾、非特殊吸附钾、非交换性钾、矿物钾及全钾含量，且降低矿物钾比例的同时提高其余几种形态钾的比例。与定位开始相比，两种类型土壤各形态钾含量和比例随时间变异特点不同，两定位点土壤矿物钾和全钾含量均表现下降。【结论】整体看直接施用化肥钾的效果优于秸秆还田。但从提高作物产量和缓解土壤钾素下降来看，小麦秸秆还田是一个有效的补钾措施。     

Dynamics of organic carbon and nitrogen in deep soil profile and crop yields under long-term fertilization in wheat-maize cropping system

Soil organic carbon(SOC) and nitrogen(N) are two of the most important indicators for agricultural productivity. The primary objective of this study was to investigate the changes in SOC and N in the deep soil profile(up to 100 cm) and their relationships with crop productivity under the influence of long-term(since 1990) fertilization in the wheat-maize cropping system. Treatments included CK(control), NP(inorganic N and phosphorus(P) fertilizers), NPK(inorganic N, P and potassium fertilizers),...     

长期施肥下中国主要粮食作物产量的变化

 【目的】阐明长期不同施肥下中国主要粮食作物产量变化态势及其差异,为评价和建立长期施肥模式、促进粮食持续生产提供依据。【方法】对中国主要长期试验不施肥（CK）、施化肥（NPK）、化肥配施有机肥（NPKM）3个处理的玉米、小麦、水稻等粮食作物产量700多组数据进行整理和统计分析。【结果】长期不施肥的玉米和小麦产量总体上表现为极显著（P＜0.05）下降趋势,年下降量分别为110.9和33.4 kg?hm-2,而水稻产量基本保持稳定。施用化肥,玉米、小麦和水稻的产量均呈极显著（P＜0.01）下降趋势,年平均下降量分别为90.9、48.5和25.3 kg?hm-2。化肥配施有机肥,3种作物的产量随时间没有显著变化,均比较稳定,与NPK比较,玉米、小麦和水稻产量变异系数分别降低了8%、4%和3%。3种作物比较,小麦和玉米产量年际间变异较大,而水稻产量相对稳定。施肥的作物产量与不施肥的作物产量（反映土壤基础地力）呈极显著（P＜0.01）正相关,基础地力产量每增加一个单位,施肥产量增加量NPKM处理比NPK处理小0.12～0.31 kg?hm-2?a-1,表明长期施用化肥作物产量对基础地力的依赖程度高于化肥配施有机肥（NPKM）。【结论】中国农田长期不施肥或施用化肥的作物产量变化趋势为玉米和小麦下降,水稻基本稳定;化肥配施有机肥具有明显的增产和稳产效果,是农业生产可持续性的施肥模式。     

Effects of long-term organic fertilization on soil microbiologic characteristics,yield and sustainable production of winter wheat

We investigated the soil microbiologic characteristics, and the yield and sustainable production of winter wheat, by conducting a long-term fertilization experiment. A single application of N, P and K (NPK) fertilizer was taken as the control (CK) and three organic fertilization treatments were used: NPK fertilizer+pig manure (T1), NPK fertilizer+straw return (T2), NPK fertilizer+pig manure+straw return (T3). The results showed that all three organic fertilization treatments (T1, T2 and T3) significantly increased both soil total N (STN) and soil organic carbon (SOC) from 2008 onwards. In 2016, the SOC content and soil C/N ratios for T1, T2 and T3 were significantly higher than those for CK. The three organic fertilization treatments increased soil microbial activity. In 2016, the activity of urease (sucrase) and the soil respiration rate (SRS) for T1, T2 and T3 were significantly higher than those under CK. The organic fertilization treatments also increased the content of soil microbial biomass carbon (SMBC) and microbial biomass nitrogen (SMBN), the SMBC/SMBN ratio and the microbial quotient (qMB). The yield for T1, T2 and T3 was significantly higher than that of CK, respectively. Over the nine years of the investigation, the average yield increased by 9.9, 13.2 and 17.4% for T1, T2 and T3, respectively, compared to the initial yield for each treatment, whereas the average yield of CK over the same period was reduced by 6.5%. T1, T2, and T3 lowered the coefficient of variation (CV) of wheat yield and increased the sustainable yield index (SYI). Wheat grain yield was significantly positively correlated with each of the soil microbial properties (P<0.01). These results showed that the long-term application of combined organic and chemical fertilizers can stabilize crop yield and make it more sustainable by improving the properties of the soil.     

黄壤旱地玉米氮、磷、钾肥料利用率及其肥效

根据贵州黄壤肥力与肥料效益长期监测的部分试验结果.分析探讨了贵州黄壤旱地玉米氮、磷、钾肥料利用率及肥料效益.结果表明,黄壤旱地玉米氮肥利用率平均为40.6%.氮、磷、钾肥配合施用比单施氮肥其肥料利用率提高6%;磷肥利用率平均为9.3%,在施用氮肥的基础上增施钾肥对提高磷肥利用率效果不大;钾肥利用率很低,平均仅为4.9%,施用钾肥的效果不明显.黄壤旱地玉米1 kg纯氮的增产量平均为16.0kg,氮、磷、钾肥配合施用比单施氮肥增产2.4 kg,平均提高16.22%;1 kg纯P的增产量平均为17.5 kg;1 kg纯K的增产量平均为2.8kg.黄壤旱地玉米施肥建议以氮、磷肥为主,钾肥应少施或不施.     

Effects of long-term full straw return on yield and potassium response in wheat-maize rotation

The effect of long-term straw return on crop yield, soil potassium(K) content, soil organic matter, and crop response to K from both straw and chemical K fertilizer(K_2SO_4) were investigated in a fixed site field experiment for winter wheat-summer maize rotation in 6 years for 12 seasons. The field experiment was located in northern part of North China Plain with a sandy soil in relatively low yield potential. Two factors, straw return and chemical K fertilizer, were studied with two levels in each factor. Field split design was employed, with two straw treatments, full straw return of previous crop(St) and no straw return, in main plots, and two chemical K fertilizer treatments, 0 and 60 kg K2 O ha~(–1), as sub-plots. The results showed that straw return significantly increased yields of winter wheat and summer maize by 16.5 and 13.2% in average, respectively, and the positive effect of straw return to crop yield showed more effective in lower yield season. Straw return significantly increased K absorption by the crops, with significant increase in straw part. In treatment with straw return, the K content in crop straw increased by 15.9 and 21.8% in wheat and maize, respectively, compared with no straw return treatment. But, straw return had little effect on K content in grain of the crops. Straw return had significant influences on total K uptake by wheat and maize plants, with an increase of 32.7 and 30.9%, respectively. There was a significant correlation between crop yield and K uptake by the plant. To produce 100 kg grain, the wheat and maize plants absorbed 3.26 and 2.24 kg K2 O, respectively. The contents of soil available K and soil organic matter were significantly affected by the straw return with an increase of 6.07 and 23.0%, respectively, compared to no straw return treatment. K_2SO_4 application in rate of 60 kg K2 O ha~(–1) showed no significant effect on wheat and maize yield, K content in crop straw, total K uptake by the crops, soil available K content, and soil organic matter. The apparent K utilization rate(percentage of applied K absorbed by the crop in the season) showed difference for wheat and maize with different K sources. In wheat season, the K utilization rate from K_2SO_4 was higher than that from straw, while in maize season, the K utilization rate from straw was higher than that from chemical fertilizer. In the whole wheat-maize rotation system, the K absorption efficiency by the two crops from straw was higher than that from K_2SO_4.     

长期不同施肥对东北黑土区玉米产量稳定性的影响

【目的】通过阐明长期不同施肥下东北黑土区玉米产量的变化规律及其稳定性差异,为建立合理施肥模式、促进东北黑土区玉米持续稳产和高产提供科学依据。【方法】以（公主岭）国家黑土肥力与肥料效益长期试验为研究平台,利用8种不同施肥模式（CK、NP、NK、PK、NPK、M₁NPK、SNPK和M₂NPK）的25年数据分析玉米产量变化及土壤养分状况对施肥模式的响应。【结果】长期有机肥与化肥配施玉米产量总体上表现为上升趋势,有机肥氮替代部分化肥氮的有机无机配施处理增产效果也较为明显;M₁NPK、SNPK和NPK 3个等氮量施肥处理玉米平均产量差异不显著,其前11年NPK处理玉米产量高于SNPK和M₁NPK处理,后14年NPK处理玉米产量低于SNPK和M₁NPK处理;施化肥处理玉米平均产量（1990-2014年）排序为NPK＞NP＞NK＞PK、CK。氮、磷和钾肥对玉米产量的增产效应差异较大,每千克氮肥、磷肥和钾肥的产量效应分别为33.0、16.2和15.3 kg。有机无机配施处理玉米产量可持续指数（SYI）值高,分布在0.712-0.798,玉米产量可持续性好,而不平衡施肥和不施肥处理的SYI值最低;CK、PK和NK处理玉米产量变异系数较大,分布在18.5%-34.7%,产量稳定性差,而有机无机配施处理相对较小都在10.8%-13.0%。在施肥处理中,PK处理平均生产力贡献率最低,仅为37.8%,但与氮配施平均生产力贡献率达到91.2%;NPK、M₁NPK与SNPK 3个等氮量施肥处理平均生产力贡献率差异不显著。长期施用有机肥可明显提高土壤有机质、全氮、有效磷和速效钾含量,施用化肥磷对土壤有效磷含量提高较显著,但施用化肥氮和钾分别对土壤全氮和速效钾含量提高效果不显著;通过相关性分析可知玉米产量与土壤有机质、全氮和速效磷均呈极显著正相关（P＜0.01）,而与土壤速效钾含量呈显著正相关（P＜0.05）。【结论】长期不施肥或偏施化肥玉米产量的稳定性减弱、土壤生产力贡献率下降;平衡施用化肥可有效提高黑土区玉米产量稳定性和可持续性;有机肥与化肥配施具有明显的增产和稳产效果。因此,施用有机肥氮替代部分化肥氮的有机无机配施模式是东北黑土区最有效的施肥措施。     

施肥对潮土养分非匀衡化的土壤修复研究

[目的]研究施肥对不同处理的土壤修复作用。[方法]利用盆栽试验对长期不合理施肥导致土壤养分失衡及生产力下降的土壤进行施肥修复。[结果]试验结果表明：有机、无机肥配合施用是快速修复土壤养分和提高生产力的最佳方法;NP、NPK是既均衡土壤肥力又提高作物产量的无机肥施用方式;对土壤有效磷、氮极度缺乏的土壤,单施磷肥、氮肥效果极显著,其肥效在小麦上与NPK相同。[结论]长期施化肥的土壤对化肥的依赖性更强,停止施肥,玉米产量下降78.6%,小麦产量下降52.8%;而长期施NK和PK肥的土壤,停止施肥反而产量增加,NK处理玉米产量提高112%,小麦产量增加182%,PK处理中玉米产量增加15.1%,小麦产量增加59%;单施有机肥的当季效果不如化肥,但后效明显好于化肥。     

土壤磷钾供应能力研究

为给冬小麦-夏玉米高产提供合理施肥和培肥土壤的科学依据,采用田间试验法,在河北省宁晋县大陆村镇试验地,研究该地土壤磷钾供应能力。结果表明,冬小麦季,土壤磷素贡献率达100%,钾素贡献率为94.5%;不施肥处理的土壤供P、K量分别为55.4和139.2 kg/hm^2,NP配施土壤供K量比对照提高15.7%;NK配施土壤供P量比对照提高6.3%。施入钾肥改善了冬小麦的株高、基本苗数、分蘖数、总茎数、成穗数、穗粒数和最终产量,提高土壤的钾素营养。增施磷肥,不能增加冬小麦产量,只能增加生产成本,造成土壤中磷的残留增多。对照区土壤中的磷钾在支持6 750 kg/hm^2的小麦产量后,还能继续满足9 810 kg/hm^2的夏玉米需求,说明供试土壤补钾能显著提高冬小麦产量,土壤中的磷钾不是限制夏玉米产量的主要因素。     

湖北省不同稻作区域秸秆还田替代钾肥效果

【目的】研究不同稻作区域钾肥和秸秆还田对水稻产量、钾素吸收量以及农田钾素表观平衡的影响,分析不同稻区秸秆还田可替代化学钾肥的用量,为不同区域稻田秸秆还田条件下钾肥的合理配置提供理论依据。【方法】2013年在湖北省鄂东丘陵、鄂中丘陵岗地和江汉平原3个区域的19个县（市）布置稻田秸秆还田替代钾肥效果研究田间试验,试验共设置6个处理：分别为（1）不施钾（NP）;（2）施化学钾肥（NPK）;（3）施秸秆（NP+S）;（4）秸秆还田配施1/2化学钾肥（NP+1/2K+S）;（5）秸秆还田配施3/4化学钾肥（NP+3/4K+S）;（6）秸秆还田配施全量化学钾肥（NPK+S）。【结果】不同稻作区钾肥和秸秆均能不同程度增加水稻产量和地上部钾素吸收量。与NP处理相比,鄂东丘陵区、鄂中丘陵岗地区和江汉平原区NPK处理水稻分别增产0.36、0.36和1.07 t·hm^-2,平均增产率分别为6.4%、5.0%和15.3%;而施秸秆（NP+S）处理水稻分别平均增产0.57、0.49和0.24 t·hm^-2,增产率为7.6%、6.9%和4.0%。3个稻作区施化学钾肥（NPK）地上部钾素吸收量平均增加20.1-61.9 kg K₂O·hm^-2,施秸秆（NP+S）钾素吸收量平均增加8.5-39.1 kg K₂O·hm^-2,江汉平原区施化学钾肥处理产量和钾素吸收量均显著高于施秸秆处理,而鄂东丘陵区和鄂中丘陵岗地区NP+S与NPK处理的产量和钾素吸收量均没未表现出差异。通过计算土壤-作物系统钾素表观平衡,发现一季水稻收获后土壤钾素均处于亏缺（平均钾素亏缺量为144.3-284.4 kg K₂O·hm^-2）状态,但秸秆还田处理亏缺量小于秸秆不还田处理。在保证水稻产量（即NPK处理产量）时秸秆还田条件下,采用模型计算出鄂东丘陵区、鄂中丘陵岗地区和江汉平原区的平均钾肥用量分别比目前钾肥推荐用量（60 kg K₂O·hm^-2）节约化学钾肥66.8%、75.2%和9.7%;参考2013年钾肥和水稻价格,可计算出秸秆还田条件下鄂东丘陵区、鄂中丘陵岗地区和江汉平原区最经济钾肥推荐用量分别比推荐用量节省化学钾肥54.3%、53.5%和36.9%。【结论】湖北省不同稻区均可采用秸秆还田的方式减少钾肥投入,不但可以缓解土壤钾素亏缺,而且对农田钾素的可持续管理具有重要意义。     

长期定位施肥对强筋小麦郑麦9023产量和品质的影响

在“国家潮土肥力监测与肥料效益长期定位监测基地”15年不同施肥制度的基础上,研究了不同施肥处理对强筋小麦郑麦9023产量和品质的影响。结果表明:NP和NPK处理的小麦产量、穗粒数、穗数、蛋白质组分含量和蛋白质产量、湿面筋产量较其他处理有明显的提高,且形成时间明显缩短,稳定时间较长,弱化度减小;N和NK处理的小麦千粒重、蛋白质含量、湿面筋含量较其他处理有明显的提高,但是小麦产量、蛋白质和湿面筋产量最低;有机无机肥配施处理的产量均与NPK处理差异不显著,千粒重、穗数、蛋白质含量均较NPK处理高,以增施有机肥料(1.5MNPK)处理表现最为明显;秸秆还田(SNPK)能够增加蛋白质组分含量。在生产实践中,无机肥料和有机肥料合理配施,不仅能够改良土壤,还有利于提高小麦产量和改善品质,是保证小麦高产、稳产、优质的施肥措施。     

稻草还田配施化肥对小麦养分吸收和产量的影响研究

重庆地区中性紫色土属中钾少磷缺氮型。稻草还田可增加土壤养分贮备,维持 P、K 活性,但对当季小麦的影响则与配施化肥类型有关,配施 NK 或 NPK 小麦养分吸收和土壤对(?)季小麦供肥量减少,籽粒/秸秆比降低。稻草与 NP 配施对土壤和作物均有良好影响。为发挥稻草的培肥土壤和增产作用,必须根据土壤、秸秆和作物养分供需状况,调节养分的平衡供应。