包膜氮肥养分释放研究

通过溶出率试验和淋溶试验对研制的2种包膜肥料ZP1，ZP2的氮素释放特征进行了研究，结果表明，ZP1的初期溶出率和养分平均释放速率均高于ZP2，包膜肥料的养分释放符合缓释／控释肥料的基本要求；ZP1有一个养分释放高峰，ZP2有两个释放高峰，2种类型肥料的养分累积释放量均符合一级动力学方程。     

不同释放期包膜控释尿素与普通尿素配施在夏玉米上的应用效果研究

通过大田对比试验研究了释放期为30 d、60 d、90 d的包膜控释尿素(分别用PCU30、PCU60、PCU90表示)与普通尿素(U)配合一次性基施对夏玉米产量、氮肥利用率、氮素积累量及经济效益的影响。结果表明:在施氮量相等、包膜控释氮素占总施氮量30%的条件下,不同释放期的包膜控释尿素(PCU30、PCU60、PCU90)与普通尿素配合一次基施比习惯施肥显著增加夏玉米产量和氮素积累总量,提高氮肥利用率和经济效益,其中PCU60与普通尿素配合一次基施玉米产量最高,为8778 kg/hm2,增产12.0%;氮素积累总量为201.5 kg/hm2,增加18.9%;氮肥利用率提高11.02个百分点;经济效益为11468.7元/hm2,提高产量10.7%。     

新型包膜肥在早熟禾上的试验研究

通过自制长效包膜肥与常规施肥在草地早熟禾盆栽上的试验研究表明,在同一施肥量的情况下作基肥一次施入,长效包膜肥在整个试验期间可以满足早熟禾整个试验期对养分的需求,但常规施肥则出现了缺肥症状。包膜肥加工过程及加入缓释剂对N素养分和P、K养分的释放规律有所不同:缓释剂的加入有利于提高N肥效但却加速了肥料中P、K的释放;包膜却对N、P、K均有延缓释放的作用。     

新型大球包膜控释肥在土壤中的淋溶特征

通过土柱淋溶模拟试验研究果树专用新型大球包膜控释肥在土体中的淋溶特征以及对土壤淋滤液pH、EC变化和N、P、K、Mg等养分淋失的影响.结果表明,新型大球包膜控释肥处理淋滤液pH值显著高于未包膜肥料处理,但与不施肥处理和其他2种控释肥处理差异不显著.在整个淋溶过程中,新型大球包膜控释肥处理淋滤液EC值和淋滤液中无机态氮、水溶性磷、水溶性钾含量在淋溶前期显著低于速效肥料处理,但在淋溶后期显著高于其他2种控释肥处理.新型大球包膜控释肥无机态氮、水溶性磷和水溶性钾的淋溶损失率分别为38.72％,1.91％和24.76％.新型大球包膜控释肥与未包膜肥料相比显著减少了养分的淋溶损失,降低了施肥对地下水质的影响.     

桐油包膜尿素的养分释放速度及其对黑麦草生长的影响

表征了4种供试桐油包膜尿素(TCU)的特性和包膜形貌,测定了其养分释放曲线和释放速度。在不施基肥以及基施氮素15.8g/m2的尿素和4种TCU的情况下,用盆栽试验考察了各施肥处理对黑麦草生长、形态指标和色泽的影响。结果表明,所有施肥的处理均有助于黑麦草的出苗,在播种后的最初4～5周,TCU和尿素处理的黑麦草植株高度和生物量均优于未施基肥的处理,施肥处理间的差别不大;在播种的5～6周后,具有长释放周期的TCU.UT-02(t8024d)和UC-04(t8026d)处理的黑麦草植株高度和生物量均超过了施尿素的处理,这些TCU处理的黑麦草的绿期长于7周,也优于尿素处理的黑麦草的绿期5周。     

包膜复合肥对夏玉米产量、氮肥利用率与土壤速效氮的影响

以郑单958为材料,比较研究了复合肥(CF)与包膜复合肥(CCF)对华北平原夏玉米产量、氮肥利用率及土壤速效氮与土壤氮素表观盈亏的影响。结果表明,1)玉米产量随施氮量增大而增大,施N.180.kg/hm2时,CCF处理高于CF处理,施N.90.kg/hm2时表现相反;2)与CF处理比较,CCF处理施N.180.kg/hm2时,氮肥利用率高5.3个百分点,施N.90.kg/hm2时低2.4个百分点;3)土壤速效氮含量一般随施氮量增大而提高,各时期表土层CCF处理较CF处理高,中、下土层表现相反。大喇叭口期之前,CF处理中、下土层土壤速效氮含量高于上土层(020.cm或040cm),而CCF180处理060.cm土层高于60120.cm土层;4)不施氮,各生育阶段均出现土壤氮素表观亏缺,且吐丝后亏缺量占总亏缺量近80%;土壤氮素表观亏缺量随施氮量增大而降低,两种肥料表现一致;同等施氮量下CCF处理亏缺量较CF处理低。包膜复合肥氮素释放较平稳,对土壤速效氮向下运移的控制较好,有利于减少氮素潜在的淋洗损失。综合考虑产量、氮肥利用与氮素损失等因素,包膜复合肥用量N.180.kg/hm2是吴桥试区夏玉米季较为理想的选择。     

无机包膜肥料在提高小麦氮素利用率和产量效应的研究

A field experiment with winter wheat （Triticum aestivurn L.） was conducted on a silt loam calcaric endorusti-ustic Cambosols derived from the Yellow River alluvial deposits in Henan, China, from 2001 to 2002 to evaluate N recovery and agronomic performance of different mineral coated fertilizers （MiCFs） compared to normal urea used in wheat cropping systems under field conditions. Five treatments, including CK （check, no N fertilizer）, urea and three different MiCFs at an equivalent N application rate were established in a randomized complete block design. N release from MiCFs in soil was more synchronous with the N requirement of wheat throughout the growth stages than that from urea, with grain yield of the MiCF treatments significantly higher （P 〈 0.05） than that of the treatment urea. Correspondingly, the N recovery rate was greater for all MiCFs compared to urea, increasing from 32.8% up to 50.1%. Due to its high recovery and low cost, use of the mineral coated N fertilizers was recommended instead of the polymer coated N fertilizers.     

基于离散元的包膜肥料Bonding模型参数标定

包膜肥料是在粒状水溶性肥料表面涂覆半透水性或不透水性物质,养分通过包膜的微孔、缝隙慢慢释放出来,节肥增效作用显著。包膜肥料的养分释放特性与包膜层材料、结构紧密相关,目前常用的排肥器在排施肥料过程中会对肥料颗粒造成不同程度的机械损伤,导致包膜层破坏。为设计适用于包膜肥料无损排施的排肥器,同时缩短研发周期,采用离散元软件中的Bonding模型建立肥料颗粒仿真模型。为提高仿真精度,需对Bonding模型进行参数标定。首先通过单轴压缩试验得到包膜肥料颗粒的实际极限破碎位移和极限破碎载荷,在离散元软件中以此为目标依次通过Placket-Burman试验、Steepest ascent试验和Box-Behnken试验确定最优的Bonding模型参数组合。最优条件下单轴压缩试验表明,极限破碎位移和极限破碎载荷与实际值的相对误差分别为0.222%、0.554%。借助外槽轮排肥器验证所得标定参数组合的可靠性,以肥料颗粒破碎率为指标,得到实际与仿真中肥料颗粒破碎率相对误差不大于11.40%,满足施肥机械设计参数优化需求,可为研究包膜肥料颗粒机械破碎机理、优化设计无损排施的新型排肥器提供参考。     

不同水稻种子包衣剂比较试验

通过 3个不同来源的水稻种衣剂进行试验分析 ,结果表明 :合肥丰乐农化厂的种衣剂对种子发芽率、水稻生育期没有影响 ,对秧苗素质有明显的促进作用 ,对苗期稻瘟病具有较高的抗性 ,且有明显的增产效果 ,小区产量显著优于两对照种衣剂处理     

Effects of palm fat powder and coated folic acid on growth performance,ruminal fermentation,nutrient digestibility and hepatic fat accumulation of Holstein dairy bulls

This study evaluated the effects of palm fat powder(PFP) and coated folic acid(CFA) on growth performance, ruminal fermentation, nutrient digestibility, microbial enzyme activity, microflora, hepatic lipid content and gene expression in dairy bulls. Forty-eight Chinese Holstein bulls((362±12.4) days of age and(483±27.1) kg of body weight(BW)) were assigned to four groups in a completely randomized design with a 2×2 factorial arrangements. Supplemental PFP(0 or 30 g PFP kg~(–1) dietary dry matter(DM)) and CFA(0 or 120 mg FA d~(–1) as CFA) were mixed into the top one-third of a total mixed ration. The study included a 20-day adaptation period and followed by a 90-day collection period. The lower(P0.01) feed conversion ratio with PFP or CFA addition resulted from the constant DM intake and the higher(P0.05) average daily gain. The higher(P0.05) ruminal p H, ether extract digestibility, microbial α-amylase activity, Butyrivibrio fibrisolvens copy, and expression of peroxisome-proliferator-activated receptor α(PPARα) and carnitine palmitoyl transferase~(-1)(CPT1), and lower ruminal total volatile fatty acids(VFA) concentration, acetate to propionate ratio, neutral detergent fibre(NDF) digestibility, copies of total protozoa and Ruminococcus flavefaciens, and expression of sterol regulatory element binding protein~(-1)(SREBP1) and acetyl-coenzyme A carboxylase α(ACACA) were observed for PFP addition. Supplementation with CFA increased(P0.05) ruminal total VFA concentration, acetate to propionate ratio, digestibility of DM, organic matter, crude protein and NDF, activity of cellobiase, pectinase and α-amylase, copies of selected microbial except for total protozoa, as well as expression of PPARα, but decreased(P0.05) ruminal p H, and expression of SREBP1 and ACACA. The PFP×CFA interaction(P0.05) was observed for ammonia N, hepatic TG content, and m RNA expression of CPT1 and FAS. There had no significant difference in hepatic TG content when CFA was supplemented in the diet without PFP addition, the lower(P=0.001) hepatic TG content was observed when CFA was supplemented in the diet with PFP addition. The higher(P0.05) m RNA expression of CPT1, and the lower(P0.05) m RNA expression of FAS and ammonia N concentration were observed when CFA was supplemented in diet either without or with PFP addition. The results indicated that supplementation of CFA in PFP diet was more effective on increasing hepatic CPT1 expression, and decreasing ammonia N, hepatic TG content and FAS expression than in diet without PFP. Supplementation with PFP or CFA improved growth performance of dairy bulls by promoting nutrient utilization, microbial enzyme activity, microflora, and hepatic gene expression.