【作者】 张步翀；

【导师】 黄高宝；

【作者基本信息】 甘肃农业大学 ， 作物栽培学与耕作学， 2000， 硕士

【摘要】 通过在陇东半湿润偏旱区98-99年度试验集雨补灌对冬小麦/玉米带田土壤水分、光合性能、产量表现的影响研究，结果表明：1 冬小麦/玉米复合群体土壤水分时间变化动态。该区冬小麦/玉米带田的组分小麦0-30cm、30-60cm、60-90cm、0-90cm土层深度全生育期土壤含水量（重量％）以播前最高（分别为17.55％，15.18％，15.40％，16.04％），出苗后含水量持续下降，至小麦扬花—灌浆期稍有回升，随后又有所下降（0—30cm土层除外），至成熟期土壤含水量约为播前的47％左右（8.28％，6.41％，7.45％，7.37％），而且整个0—90cm土层土壤含水量与60—90cm土层变化趋势相似；带田玉米0—30cm、30—60cm、60—90cm、0—90cm土层深度土壤含水量变化较为一致，基本上呈以小喇叭口期为峰值 （19.03％，17.19％，14.98％，17.05％）的“单峰”曲线，至玉米成熟期土壤含水量降至全生育期的最低点（约为播前的33％，分别为4.64％，4.14％，7.06％，5.28％）。分析比较表明，带田冬小麦限量补灌对土壤水分的的贡献以拔节期最高，抽穗期稍次之，而扬花水和灌浆水的贡献远较前两个时期为低，并且灌浆期灌水优于扬花期灌水；带田玉米限量补灌对土壤水分的贡献大小按生育期依次为大喇叭口期＞抽雄开花期＞吐丝期＞灌浆期，即灌水越早，灌水对土壤水分的贡献越大。2 冬小麦/玉米复合群体土壤水分中间变化动态。无论灌水与否，小麦自抽穗期，玉米自六叶期开始30—60cm土层土壤水分（mm）就明显低于0—30cm土层和60—90cm土层，并且从小麦拔节期和玉米六叶期开始各带田处理三个土层深度土壤含水量均低于单作对照小麦玉米。经分析比较发现，由于灌水的近期效应，小麦玉米自灌水后的第二个测定生育期开始不同深度土层土壤含水量占整个0—90cm土层总含水量的比重保持在一个较为稳定的水平上，但却因灌水时期不同而异。3 运用回归分析，建立了冬小麦、玉米各处理全生育期土壤含水量W（重量％）随时间t（播后日数d）变化的数学模型，发现小麦W与t之间的关系可用回归方程W=c/(1+e^a-bt)来表示，玉米W与t之间的关系可用方程W=ae^{bt^2}来表示，并且均达显著相关。4 就带田整体而言，灌水处理相对生产力远高于不灌水处理，灌水比不灌水具有显著的增产效应，增产幅度在13.0％—40.8％之间，以WC3处理产量最高，为12787.0kg/hm²，增产幅度40.8％，WC5处理产量最低，为10258.9kg/hm²，增产13.0％，故复合群体限量灌水的增产效果为小麦抽穗期、玉米抽雄开花期（WC3）＞小麦扬花期、玉米吐丝期（WC4）＞小麦拔节期、玉米 大喇叭口期（WCZ）＞小麦、玉米灌浆期（WCS）＞不灌水（WCI），由此确 定该区冬小麦／玉米带田限量补充灌水的最佳生育期为小麦抽穗期、玉米抽雄 开花期。水分利用率（WUE）带田灌水处理均高于不灌水处理，其变化与带田 产量具有一致性，即水分利用率大小亦为 WC3门．800kgnun”’hln“z)＞WC4 （14．981 kgmm＊inn2）＞WCZ （1＊72k删＊hm2）＞WCS（12＊57k删‘hln上） ＞WCI（12．269kpolhln－2）。 s 带田冬小麦全生育期单叶和群体光合速率阶变化均呈“双峰”曲线，单 口 Pn 以拔节期和抽穗期为双峰，分别为 10．31 CO。mgdm二V’和 14．54 CO。mgdm“、－’，群体 Pn以孕穗期和灌浆期为峰值，分别为 9石4 CO。mgdm”、“’ 和 5石2 CO。mgdm、”‘，而且除孕穗期外单叶光合速率均显著高于群体光合速 率。无论是单叶还是群体，灌水处理光合速率均高于不灌水处理，且早灌比迟 灌要好，同时限量补灌对光合速率的作用具有近期效应，随着灌后日数的增加， 灌水与未灌水处理间Pn的大小逐渐接近一致。 6 复合群体叶面积指数 LA 变化呈以小麦灌浆初期和玉米吐丝期为峰值 （2．56 cm’／cm’和 4．96 cm’／cm 2） 的“双峰”曲线，其谷点出现在玉米小喇叭口 期（l．53 cm’／cm’）。限量灌水处理全生Ti期平均LAI（2．37 cm‘／cm‘）高于不灌 水处理(2．26 cm’／cm勺，但灌水处理间差别不明显；全生育期总叶日积LAD带 田（364．76 d）高于单作（小麦为 284．sld，玉米为 283．63 d），且灌水处理（368．gi d）均高于不灌水处理（348．17 d），充分显示出带田 LAD优势。限量补灌对总 LAD 的贡献与产量表现亦具有一致性。总LAD 与产量Ye 的相关方程为 Ye－138．578LAD－39402．16(FO．8899378＼ 7 复合群体 CGR与 NAR变化均呈以小麦拔节一抽穗期（分别为门．37 gm勺’ 和 8＊9 gm习Zd＊）和玉米小喇叭口一大啤①口期(分别为 22＊9 gm二d＊禾 9＊9 gm－Z更多还原

【Abstract】 Field experiment and research in LongDong dry land area between year 1998- 1999 showed that: 1. The timeline change of soil moisture in winter wheat/corn intercropping For Winter wheat of wheat/corn intercropping in 0-30cm, 3 0-60cm, 60-90cm. and 0?0cm depth in Soil layer throughout whole growth stage, the highest soil water content(SWC) was in presowing stage (i.e. 17.55%, 15.18%, 15.40%, 16.04% respectively), while a continuous decreasing of that was seen after sowing before a slight restoration in flowering to filling sta2 except 0-30cm depth. Till maturity SWC was about 47% of that of presowing (8.28%, 6.4 1%, 7.45%, 7.37% respectively), and a tendency was found that SWC in average 90cm depth is similar as that in 60-90cm depth. For corn the change of SWO in each layer throughout the whole growth stage showed a consistency with a ingle Peak?curve in small horn stage (19.03%, 17.19%, 14.98%, 17.05% respectively), and reached their lowest point in maturity stage, which was about 33% of that ofpresowing, i.e. 4.64%, 4.14%, 7.06%, 5.28% respectively. Analysis and comparation indicated that the highest contribution to soil water by limited irrigation in all growth stages for wheat is in jointing stage(JS) and then heading stage (HS) , and flowering stage (FS) follows it, while in filling stage(FLS) see its lowest SWC. For corn the sequence is large horn stasre(LHS), heading and flowering stage(HFS), silking stage(SS), and FS, that is to say, the earlier irrigation, the more contribution to soil moisture. 2. The vertical change of soil moisture in winter wheat/corn intercropping. Whether irrigated or not, SWC (mm) of winter wheat since HS and of corn since Six-leaf Stage(SLS) in 30-60cm depth become gradually lower than that of in 0-30cm and 60-90cm depth and SWC in these three diffent depths in intercropping treatments also become lower than that of in sole winter wheat and corn respectively since JS of winter wheat and SLS of corn. Analysis and comparation indicated that percentage of SWC in different depth since the 2th growth stage after irrigation of wheat and corn began to keep on a stable level, but the percentage varied with the change of irrigation time. 2. With the aid of regression analysis simulation models were developed in each winter wheat/corn treatment through all growth stages, which is expressed as equation Wc/(l+ea.bt) for wheat and Waebt2 between W(SWC, %) and t (days after sowing). 45 4. As far as the compound intercropping canopy is concerned, relative productivity under limited irrigation conditions was much higher than that of no irrigation treatment. Furthermore, significant effects of yield increasing in irrigation treatments were found by a 13.0-40.8 percent more in Economic Yields (Ye) than that of no irrigation treatment, i.e. the highest Ye under irrigation conditions was 12787.0 kg/bin2, while the lowest Ye was 10258.? Kg/bIn2. For wheat/corn canopy the most appropriate sequence of growth stages regarded as irrigation time by yields increasing was wheat uS and corn HFS (WC3 treatment). wheat FS and corn SS (WC4 treatment), Wheat JS and corn LHS (WC2 treatment), wheat and corn FLS (WC5 treatment). and no irrigation treatment (WC 1). So wheat HS and HFS was considered as the best irrigation time for wheat/corn cc mpound canopy. In the other hand, Water Use Efficiencies (WUE) in all irrigation treatments were higher than that of no irrigation treatment, which was the same consistency as Ye. That is to say, for WUE the sequence from hi更多还原