养分平衡法在玉米测土推荐施肥中的应用效果

通过小区试验研究,玉米产量和化肥利用率在不同的施肥技术条件下存在差异。其优化次序为:NPK有机肥>NPK>NP>NK>N>PK>ck;深施NPK有机肥>深施NPK>常规施NPK>薅土浅施NPK>撒施NPK>ck。根据养分平衡法建立了目标产量、空白田产量与土壤养分测定值及相应N、P、K化肥施用量的函数关系,在产前提出N、P、K肥的适宜用量和比例以及相应的施肥技术。     

冬小麦-夏玉米轮作中的磷肥推荐

本文以1986～1988年度冬小麦、夏玉米3×3多点试验数据分别建立了冬小麦、夏玉米包括土壤测试值(土壤全氮含量、Olsen-P 含量)在内的综合推荐施肥模型。通过1992年～1993年度冬小麦-夏玉米轮作施肥试验对模型进行了校验,以土壤 Olsen-P 含量变化规律将两种作物的综合推荐施肥模型联立起来。形成轮作综合推荐施肥模型。由轮作综合推荐施肥模型推导出冬小麦施用磷肥对夏玉米的后效效益方程,它与轮作试验结果十分吻合。     

利用OLE技术集成Delphi与MapInfo开发棉田土壤肥力信息管理与施肥决策系统

以新疆兵团农五师81团为系统试行和合作地点,针对土壤肥力信息数据在农业生产中的重要作用,将Delphi强大的数据库编程能力和MapInfo的图形表达能力有机结合,实现了MapInfo的集成二次开发,建立了集棉田土壤养分信息管理、土壤施肥推荐、GIS条田图形信息管理功能于一体的新疆农五师81团棉田土壤肥力信息管理与施肥推荐决策系统.     

滹沱河（石家庄市区段）植物资源调查及物种推荐

对滹沱河（石家庄市区段）进行的生态开发整治工程是石家庄市政府提出的重点工程,而植被的恢复与重建是对退化生态系统进行修复的有效手段。通过资料收集和实地调研相结合的方法,认为该区域内共有植物75科211种,并从植物的生态功能角度对植物种类进行了推荐,希望能为研究区域植被群落的恢复提供一些参考。     

氮磷钾肥对马铃薯营养状况及块茎产量的影响

试验分别在甘肃省景泰县、内蒙古自治区达拉特旗和河北省沽源县3个马铃薯生产基地进行,在基地常规N、P2O5、K2O肥施用量分别为300、345、375kg/hm2的基础上,研究改变磷、钾、氮肥用量对马铃薯营养状况、块茎产量以及土壤养分的影响。试验结果表明,氮、磷、钾肥用量分别从N300、P2O5345、K2O375kg/hm2降低到180、180、225kg/hm2,对植株干物质累积量没有显著影响,3个基地都呈相同的趋势;3个基地不同处理的块茎产量也没有显著性差异。因此,在试验条件下,氮、磷、钾肥用量和比例为180-180-225的施肥处理,其经济效益较高。施肥对土壤养分含量有较大的影响,特别是磷肥,当施用磷肥后,土壤速效磷含量显著提高,而且主要存在于表层土壤(0￣20cm),这说明缺磷土壤通过施用磷肥,可提高土壤有效磷水平。     

施氮、供水对菠菜(Spinacia oleracea L.)的生长和土壤残留矿质氮的影响

Effects of conventional and optimized water and nitrogen managements on spinach (Spinacia oleracea L.) growth and soil mineral N (N_min) residues were compared in an open field experiment in which water balancemethod and N recommendation with the KNS-system were included. It was shown that the conventionalwater treatment (seasonal irrigated amount: 175 mm) reduced spinach growth compared to the water balancetreatments (seasonal irrigated amount: 80 and 85 mm) at the same N supply level due to N loss through leaching caused by excessive water supply. Although 309 kg N ha^-1 was applied in the conventional N treatment, compared to 82 and 66 kg N ha^-1 in the optimum N treatments, no significant difference in cropyield was investigated between the N treatments with the same irrigation practice. N uptake in spinach andsoil residual Nmin contents were also significantly affected by the irrigation practices. The conventional water supply not only decreased water use efficiency, but also resulted in excessive NO₃^--N being leached below the root zone. In order to meet the same target value of N requirement for the next crop, cauliflower, based on the KNS-system, at least extra 50 kg N ha^-1 was needed in the conventional water treatments in comparison to the water balance treatment.     

Alkaline hydrolyzable nitrogen and properties that dictate its distribution in paddy soil profiles

Nitrogen (N) is a key nutrient for rice production, and its bioavailability in paddy soils is strongly coupled to soil organic matter (SOM) cycling. A better understanding of potentially available N forms in soil, such as alkaline hydrolyzable N (AH-N), and their depth distribution will support the development of best management practices to improve the N use efficiency of rice while minimizing adverse environmental effects. Fifteen rice (Oryza sativa L.) fields from Southern Brazil were selected, and stratified soil samples were taken to a depth of 60 cm before crop establishment. Selected soil physical and chemical properties were analyzed to evaluate their relationships with AH-N contents in the soil profile. The AH-N contents below 20 cm varied extensively (increased, reduced, or constant) compared with that above 20 cm. Although clay and clay + silt contents were highly correlated to AH-N for some soils, the major property dictating AH-N distribution by depth was total N (TN), as the correlation between TN and AH-N was mainly by direct effect. The proportion of TN recovered as AH-N across sites and depths presented high amplitude, and thus AH-N was not a constant N pool across depths, indicating that AH-N can be affected by soil management practices even when TN showed no major changes. The distinct distribution of AH-N across soil sampling sites and depths indicates that depths greater than 20 cm should be considered when calibrating the AH-N index for N fertilizer recommendations for flooded rice in Southern Brazil.     

配方施肥对一年生黑麦草产草量及品质的影响

通过大田试验研究了施肥对一年生黑麦草（Lolium multiflorum）“特高”的产草量及营养品质的影响,并运用概略养分分析法评价了其饲用营养价值。结果表明,配方施肥1（N450P45K90）和配方施肥2（N540P180K360）均可显著提高黑麦草鲜草产量,与不施肥处理（CK）相比分别增加了2.6倍和3.1倍;配方施肥2处理的产量比配方施肥1处理显著增产12.0%。黑麦草干物质积累速率呈先增加后降低的趋势,播种后130 d左右,日积累速率达最大值,为223.9 kg/(hm2·d)。施肥提高了黑麦草磷、钙、粗蛋白（CP）和粗脂肪（EE）含量,降低了无氮浸出物（NFE）含量。配方施肥2与配方施肥1相比,3次收获的黑麦草CP、EE和粗灰分（CA）含量均有所提高,而粗纤维（CF）和NFE含量则略有降低。两种施肥措施均可显著提高黑麦草CP、EE、CA、CF、NFE及总能量（GE）的产出,且配方施肥2对其影响程度要大于配方施肥1处理。     

二次多项式数学模型在高蛋白大豆施肥中的应用

通过田间试验,应用二次回归正交组合设计获得高蛋白大豆的二次多项式数学模型,并以此进行施肥推荐,结果表明:与当地常规施肥相比,模型推荐施肥不但可以提高大豆蛋白质含量0.9个百分点,同时还能增加纯收入356.26元/hm2。