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1.
A suitably calculated irrigation regime can improve the productivity of artificial grassland，improve the quality of pasture and enhance water use efficiency in drier areas. In this research we compared the effects of two irrigation regimes（regulated deficit irrigation at different growth stages，I1；regulated deficit irrigation over the whole growth period ，I2）on yield and quality of Bromus inermis in the Hexi Corridor. Irrigation scheduling was optimized by considering the results of field trials and simulations of irrigation scheduling in typical dry years to provide a theoretical basis for local production practices. The results showed that：The yield of B. inermis in I1 initially increased and then decreased with successive increases in the amount of water applied，while in I2 B. inermis yield showed an increasing trend across the range of irrigation rates tested. In both irrigation regimes，the crude protein content of B. inermis gradually decreased with increasing water supply，while the acid detergent fiber and neutral detergent fiber contents increased somewhat. Compared with I2，B. inermis yield was increased by 23.11% on average and crude protein content by 6. 09% on average in I1；therefore，the I1 irrigation regime was superior. Based on the field trial combined with the simulation of irrigation scheduling in a typical dry year，it was found that a treatment designated ［greening stage （75%-85% θFC），jointing stage （65%-85% θFC），and tasseling stage （65%-85% θFC），I1DF1］，irrigation frequency of 12 times，and a total irrigation amount of 521. 76 mm provided water-saving benefits and stable yield in B. inermis in the Hexi Corridor. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved. 相似文献
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Background： Post-production fractionation of wheat distillers grains with solubles（DDGS） increases their crude protein content and reduces their fiber content.This experiment was conducted to determine the effects of fractionation of wheat DDGS on apparent total tract digestibility（ATTD） and performance when fed to broiler chicks（0–21 d）.Methods： A total of 150,day-old,male broiler chicks（Ross-308 line;Lilydale Hatchery,Wynyard,Saskatchewan） weighing an average of 49.6 ± 0.8 g were assigned to one of five dietary treatments in a completely randomized design.The control diet was based on wheat and soybean meal and contained 20% regular wheat DDGS.The experimental diets contained 5,10,15 or 20% fractionated wheat DDGS added at the expense of regular wheat DDGS.Results： The ATTD of dry matter and gross energy were linearly increased（P 0.01） as the level of fractionated wheat DDGS in the diet increased.Nitrogen retention was unaffected by level of fractionated wheat DDGS（P 0.05）.Weight gain increased linearly（P = 0.05） as the level of fractionated wheat DDGS in the diet increased.Feed intake,feed conversion and mortality were unaffected by level of fractionated wheat DDGS in the diet（P 0.05）.Conclusions： Post-production fractionation of wheat DDGS improves their nutritional value by lowering their fiber content and increasing their content of crude protein and energy.These changes in chemical composition supported increased weight gain of broilers fed wheat DDGS. 相似文献
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《畜牧与生物技术杂志(英文版)》2016,(3)
Background: The current study was conducted to evaluate egg quality and egg yolk fatty acids and immunoglobulin(Ig Y) content from laying hens fed full fat camelina or flax seed.Methods: A total of 75, 48-week-old Lohman brown hens were randomly allocated to 3 treatments, with 5replicates containing 5 laying hens each replicate. The hens were fed corn-soybean basal diet(Control), or Control diet with 10 % of full fat camelina(Camelina) or flax seed(Flax) for a period of 16 wk. Hen production performance egg quality, egg yolk lipids, fatty acids and Ig Y were determined every 28 d during the experimental period.Results: Egg production was higher in hens fed Camelina and Flax than in Control hens(P 0.05). Egg weight and albumen weight was lowest in eggs from hens fed Camelina(P 0.05). Shell weight relative to egg weight(shell weight %), and shell thickness was lowest in eggs from hens fed Flax(P 0.05). No difference was noted in Haugh unit, yolk:albumen ratio, and yolk weight. Significant increase in α-linolenic(18:3 n-3), docosapentaenoic(22:5 n-3)and docoshexaenoic(22:6 n-3) acids were observed in egg yolk from hens fed Camelina and Flax. Total n-3 fatty acids constituted 1.19 % in Control eggs compared to 3.12 and 3.09 % in Camelina and Flax eggs, respectively(P 0.05). Eggs from hens fed Camelina and Flax had the higher Ig Y concentration than those hens fed Control diet when expressed on a mg/g of yolk basis(P 0.05). Although the egg weight was significantly lower in Camelina-fed hens, the total egg content of Ig Y was highest in eggs from hens fed Camelina(P 0.05).Conclusions: The egg n-3 fatty acid and Ig Y enhancing effect of dietary camelina seed warrants further attention into the potential of using camelina as a functional feed ingredient in poultry feeding. 相似文献
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In order to ascertain water consumption characteristics of typical compound green space (CGP) which composed of turf and white elm in Urumqi city. Field irrigation experiment with fixed irrigation frequency and changed irrigation quota was carried out in Hongshan Park Urumqi. The results showed that average daily water consumption (ADWC) of lawn and white elm in CGP increased with the increase of irrigation quota,and showed the same trend of single peak curve (increased first and then decreased with the development of growth period). Cumulative water consumption of CGP in each treatment varied between 668.5~996.4 mm,which increased with the increase of irrigation quota. The ratio of water consumption between lawn and elm in CGP varied from 1:1 to 1:1.2,which increased first and then decreased with the increase of irrigation quota. The crop coefficient of CGP in each treatment during May to September varied between 0.72 and 1.52,and the average value of crop coefficient in each treatment during main growth period increased with the increase of irrigation quota. Considering the water consumption and growth of CGP,in the dry year with 75% rainfall frequency,the suitable irrigation quota of similar CGP with similar maintenance level is 36 mm,and the irrigation period is 5~7 days in Urumqi city. © 2019 Ｊｏｕｒｎａｌ ｏｆ Ｒｅｆｒｉｇｅｒａｔｉｏｎ. All rights reserved. 相似文献
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The purpose of this study was to investigate the effects of estradiol （E） and progesterone （P） on mastocyte distribution in the uterus of ovari- ectomized rats. Thirty-five adult female rats were divided randomly into seven groups：one sham operated control group （ SHAM ） ; one ovariectomized group （OVX） ;three ovariectomized plus E treatment grouPs （OVX ＋E 20,100,or 500 μg/kg body weight · d） ; and two ovariectomized plus P groups （ OVX ＋ P 2 or 10 mg/kg body weight · d）. Seven days after treatment, the contents of estradiol and progesterone in serum were detected by radioimmunoassay, and mastocytes in the uterus were stained by toluidine blue staining. Results were as following： （1） Compared to ovariectomized rat, the concent ration of estradiol in serum increased by 97. 13 % in OVX ＋ E 20 （P 〈 0.05）,204. 84 % in OVX＋E 100 （P〈0.05）,and 936.45 % in OVX ＋ E500 group （P〈0.05）;the progesterone concent ration increased by 77.25 % in OVX ＋P 2 （P 〈0.05） and 235.25 %in OVX ＋P 10 group （ P 〈 0.05 ）. （2） Compared to ovariectomized rat, the number of mast cells in uteri decreased by 32.65% in OVX ＋E 20,64.50 % in OVX ＋E 100 （P〈0.05）,74.49 % in OVX＋E500 （P〈0.05） and 70.67 % in OVX ＋P 10 groups （P〈0.05）. However, the number of mast cells increased by 66.73% in OVX ＋ P 2 group （ P 〈 0.05 ） compared with OVX. The trend of mast cells number in the rat uterus was decreased gradually with the increase of estrogen or progesterone concent ration. The number of mast cells in ovariectomized rat uterus was affected by estrogen or progesterone. These results demonstrated that estrogen or progesterone directly affected the number of mast cells in the uterus of rat. 相似文献
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Oat crops are a major animal feed source in the Qinghai-Tibetan plateau and nearby areas. Typically，the crops are used for making silage rather than hay because of frequent rain at harvest in autumn. However，there is little data on how the yield，forage quality and levels of epiphytes that may affect silage quality of different oat varieties are affected by altitude. Therefore，four oat varieties（Longyan No. 3，Longyan No. 5，Baiyan No. 2 and Bayou No. 3） were planted in 8 localities forming an altitude gradient： Huangzhong （2295 m），Tianzhu （2797 m），Shandan （2860 m），Hezuo （2957 m），Haiyan （3052 m），Maqu （3474 m），Maqin （3765 m）and Chengduo （4217 m）. Measurements included crop yield and dry matter （DM），water soluble carbohydrate （WSC），crude protein （CP），neutral detergent fiber （NDF）and acid detergent fiber （ADF）contents，and counts of lactic acid bacteria （LAB），molds，yeasts and aerobic bacteria. It was found that there were significant altitude and variety effects on fresh yield，nutritional quality and microbial epiphyte counts. With increase in altitude，fresh yield，WSC，NDF and LAB counts increased（P<0.05），as much as 284. 00%，15. 49%，10.81% and 11.60% increment were observed at Chengduo site than that at Huangzhong，respectively；meanwhile DM，CP and yeast and mold counts were reduced by 15. 67%，36.27%，23.53% and 7.75% at Chengduo compared with Huangzhong site，respectively. Among the four tested varieties，Longyan No. 5 had the highest fresh yield （75605 kg·ha−1），WSC （201.4 g·kg-1 DM） and NDF （604. 2 g·kg-1 DM） at the Chengduo site，followed by Longyan No. 3. The highest CP （119.7 g· kg-1 DM） and mold counts （4.12 lg cfu·g-1 FM） were observed in Baiyan No. 2 at the Huangzhong site. Bayou No. 3 produced the highest LAB and yeast counts at Maqin and Chengduo sites. In general，Longyan No. 3 and Longyan No. 5 gave better performance at sites above 3000 m altitude；for sites below 3000 m，the four tested varieties were all found to be suitable for silage production. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved. 相似文献
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Background: This experiment was conducted to study the effect of different feed enzymes(phytase,xylanase,β-glucanase) on release rate of trace elements(Fe,Cu,Mn and Zn) in 6 commonly used feedstuffs(corn,wheat,barley,soybean meal,wheat bran,wheat middlings) by using an in vitro model,simulating the digestive processes in stomach for 2 h and then in small intestine for 6 h at 39 °C.Results: Phytase raised(P 0.05) the release rate of Cu and Zn in corn,Cu,Zn and Mn in wheat,Cu in barley,Cu,Zn and Mn in soybean meal,Zn,Fe in wheat bran and Zn,Fe,Mn in wheat middlings.The release rate of various trace elements in feedstuffs was increased after xylanase addition.Compared with the control group,the release rate of soluble Cu in corn,wheat,barley and soybean meal,soluble Zn in corn,wheat and wheat middlings and soluble of Mn in corn,wheat,barley and wheat bran increased(P 0.05) after xylanase treatment.After the treatment of β-glucanase,the release rate of soluble Cu in corn,wheat and wheat bran,soluble Fe in barley,soybean meal and wheat bran and soluble Mn in corn and wheat bran all increased(P 0.05) compared with the control group.In each feedstuff,after corresponding enzyme treatment,the contents of phytic acid,xylan and β-glucan were significantly lower than those of the control group(P 0.05).Conclusions: Results showed that bound trace elements in feedstuffs can be released by feed enzymes.It may be necessary to take the trace elements in feedstuffs into account in the actual feed preparation including feed enzymes. 相似文献
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This experiment was conducted to investigate the effects of dietary sodium acetate on lactation performance and rumen microbiota of dairy goats. Fifteen healthy Xinong Saanen dairy goat ewes with similar body weight of (53.54±3.07) kg, the same parity (2 parities) and in mid-lactation [(60±5) d] were randomly divided into 3 groups with 5 replicates in each group. Dairy goats in the control group were fed a basal diet, and those in the experimental groups were fed the basal diet supplemented with 30 (experimental group I) and 60 g/ (d.head) (experimental group II) sodium acetate, respectively. The pre-trial period lasted for 7 days and the experimental period lasted for 21 days. The milk yield of dairy goats was recorded during the experiment. At the end of the experiment, milk samples were collected to analyze the changes in milk composition, and rumen contents of dairy goats were collected from two groups (control group and experimental group II) with significant differences in milk fat percentage. Gas chromatography and 16S rDNA sequencing technology were used to analyze the rumen fermentation parameters and rumen microbial composition and structure of dairy goats. The results showed as follows: 1) compared with the control group, dietary sodium acetate extremely significantly increased the daily milk yield of dairy goats (P<0.01), and the daily milk yield in experimental groups I and II was increased by 0.29 and 0.22 kg, respectively (P<0.01); in experimental group II, the milk fat percentage was significantly increased by 1.30 percentage points (P<0.01), and the non-fat solid content in milk was increased by 3.10% (P>0.05). 2) Compared with the control group, the rumen butyric acid content of dairy goats in experimental group II was significantly decreased (P<0.01), and there was no significant difference in rumen pH, the other volatile fatty acid content and acetic acid to propionic acid ratio (P>0.05). 3) Compared with the control group, the Sobs index, Chao1 index and Ace index of rumen microbiota in experimental group II were significantly increased (P<0.05); the results of similarity analysis (ANOSIM) also showed that there were significant differences in the structure of rumen microbiota between the two groups (P<0.05). 16S rDNA sequencing results showed that at the phylum level, Bacteroidetes and Firmicutes were the dominant phyla in the rumen of the two groups of dairy goats; at the genus level, Prevotella_1 was the dominant genus in the rumen. Compared with the control group, the relative abundances of Ruminococcus_1, Ruminococcaceae_UCG-005, Prevotellaceae_UCG-004 and Lachnoclostridium_12 in rumen of dairy goats in experimental group II were significantly increased (P<0.05), while the relative abundances of Succiniclasticum and Methanobrevibacter in rumen was significantly decreased (P<0.05). 4) The results of correlation analysis showed that rumen microbiota was correlated with daily milk yield, milk fat percentage, milk protein percentage and non-fat solid content of dairy goats. In conclusion, dietary 60 g/ (d.head) sodium acetate can significantly increase the daily milk yield and milk fat percentage, significantly reduce rumen butyrate content, and improve the lactation performance of dairy goats by improving rumen microbial composition and structure. © 2023 Authors. All rights reserved. 相似文献
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This research explored the effect of different levels of phosphorus application on diurnal variation in photosynthesis and partitioning of photosynthetic products in alfalfa under drip irrigation. In particular, the relationship between photosynthetic product levels in the plant and leaf photosynthetic parameters of alfalfa was clarified. Four phosphorus（P2O5）application levels of 0（CK）,50（P1）,100（P2）and 150 kg·ha-1（P3）were used as treatments in a field experiment. Leaf photosynthetic parameters were measured with a Li-6400 portable photosynthesis instrument on sunny days from 10：00-20：00 during the early flowering stage,together with environment factors and sugar and starch content in the leaves,stems and roots. A feature of the results was a ‘photosynthetic noon-break’phenomenon across all phosphorus application treatments,and stomatal limitation was the main factor responsible for the mid-day decline of net photosynthetic rate （Pn）. Photosynthetically active radiation had the greatest impact on the Pn of alfalfa leaves,while atmospheric CO2 concentration,atmospheric temperature,and atmospheric environmental factors such as relative humidity and vapor pressure deficit based on leaf temp also affected Pn. Principal component analysis showed that alfalfa photosynthetic efficiency in the four P-treatments ranked P2>P1>P3>CK. At the 100 kg·ha-1 phosphorus level（compared to CK）,the hay yield of alfalfa was increased significantly,the soluble sugar contents of leaves,stems,and roots were increased by 11. 6%,5. 0% and 4. 6%,respectively,and the starch contents were increased by 15. 2%,9. 6% and 5. 3%,respectively. Higher overall levels of soluble sugar and starch typically manifested as greater concentration increases in leaves,and relatively smaller increases in roots and stems. The diurnal troughs in Pn,transpiration rate,leaf internal CO2 concentration and water use efficiency（WUE）of alfalfa leaves were less marked in the P treatments,compared with the control treatment. Therefore,appropriate phosphorus application can increase the photosynthetic efficiency of alfalfa leaves,thereby significantly promoting crop growth and development. At the phosphorus（P2O5）application rate of 100 kg·ha-1（P2）,the alfalfa photosynthetic enhancement effect was the most pronounced. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved. 相似文献
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不同轮作序列对旱地胡麻土壤有机碳稳定性的影响 总被引：1，自引：0，他引：1
为了探索陇中黄土高原半干旱丘陵沟壑区胡麻轮作序列对土壤碳库的影响,2012-2016年通过4年定位试验,以连作为对照,研究了不同胡麻频率下的轮作序列(F:休闲;PWFW:25%Flax、马铃薯-小麦-胡麻-小麦;WFWP:25%Flax、小麦-胡麻-小麦-马铃薯;FWPF:50%Flax、胡麻-小麦-马铃薯-胡麻;WPFF:50%Flax、小麦-马铃薯-胡麻-胡麻;FFFF:100%Flax、胡麻-胡麻-胡麻-胡麻)对土壤团聚体、总有机碳(TOC)、土壤颗粒有机碳(POC)、土壤微生物碳(MBC)和氮(MBN)的影响。结果表明,休闲、不同轮作序列和低胡麻频率显著增加了030 cm土层<0.25 mm粒级的土壤团聚体含量、TOC和POC含量,而随胡麻频率的增加三者的含量呈下降趋势。其中,25%Flax处理下土壤团聚体含量较播前和休闲处理分别显著增加了2.02%4.04%和9.56%11.73%;土壤有机碳(SOC)较连作显著增加5.95%7.48%。50%Flax处理下胡麻位置对土壤SOC影响显著,且轮作(FWPF)显著高于连作(WPFF)。060 cm土层土壤SOC含量表现为休闲>播前≈25%Flax>50%Flax>100%Flax。与连作相比,轮作显著提高了010 cm土层土壤TOC和POC含量,呈现表层富集现象。土壤POC含量表现为25%Flax≈休闲>50%Flax>100%Flax。此外,轮作换茬显著增加了土壤MBC含量,且随着胡麻频率的增加,030 cm土层土壤MBC含量逐渐降低。与播前、休闲、轮作相比,连作显著降低土壤微生物碳氮比,50%Flax(WPFF)轮作序列和土层深度对土壤有机碳和微生物量的互作效应显著。综合来看,休闲可以显著改善土壤理化性状,25%胡麻频率的轮作序列利于保持土壤团聚体稳定性,增加土壤TOC、SOC和POC含量,而50%Flax轮作序列(WPFF)能够提高土壤微生物量和微生物碳氮比。表明25%胡麻频率的轮作序列均可维持土壤有机碳的稳定性,是旱地胡麻比较理想的轮作序列。 相似文献
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采用问卷调查和调研的方式,对山东省的主要种植模式进行了详细调查研究。结果表明,山东有粮-粮、粮-经、粮-饲、经-饲等9种代表性的种植模式。每公顷年纯收入最高的前3种均为粮-饲种植模式,且饲草茬收入是粮茬的4倍以上,是收入的主要构成部分。其中经济效益最高的小麦(Triticum aestivum)+苏丹草（Sorghum sudanense）轮作模式年纯收入40 725元·hm-2。经济效益最低的是小麦+玉米(Z.mays)的种植模式,该模式下的纯收入为12 486元·hm-2。产投比最高的前3种模式均为粮-饲种植模式,比值在2.76~3.03,最低的为粮-粮模式中的小麦+玉米模式,其产投比仅为1.66。各种植模式投入比例相对较高的为材料费用和人工费用,分别占30.0%~46.3%和20%~53%;管理费用所占比例最小,为18%~29%。总之,在各种植模式中产投比较高的种植模式为粮-饲型,可在山东省内尤其是中低产田中大面积推广草田轮作。 相似文献
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为探索西北旱区利于维护农田土壤良好的理化性质的种植制度,采用大田试验,以休闲处理为对照,研究了100% Flax、50% Flax（Ⅰ）、50% Flax（Ⅱ）和25% Flax 4个胡麻种植频率,100% Flax（Cont F）,50% Flax（Ⅰ）：WFPF、FPFW、PFWF、FWFP,50% Flax（Ⅱ）：FWPF、WPFF、PFFW、FFWP,25% Flax：WPWF、PWFW、WFWP、FWPW,其中F为胡麻,P为马铃薯,W为小麦,共13个种植模式下农田土壤团聚体稳定性及其氮素含量的分布状况。结果表明：土壤团聚体平均重量直径（MWD）和几何平均直径（GMD）与分形维数（D）、团聚体破坏率（PAD）之间呈极显著负相关关系,与0.5~1.0 mm粒径中NH4+-N含量和>2 mm粒径中NO3--N含量呈显著正相关关系,团聚体稳定性的增大显著提高了土壤中硝铵态氮含量。50% Flax（Ⅰ）胡麻种植频率以及马铃薯茬口显著增加了>0.25 mm粒径大团聚体含量、MWD和GMD,显著降低了土壤的D、PAD和土壤可蚀性（K）;不同轮作模式下FWFP处理显著提高0.25~2.00 mm粒径水稳性大团聚体含量,显著增加土壤团聚体MWD和GMD和抗侵蚀能力,降低分形维数和团聚体破坏率,使其土壤团聚体结构越稳定。由此表明,FWFP轮作模式可显著提高土壤水稳性大团聚体含量,促进土壤大团聚体的形成,增加土壤团聚体稳定性,对我国北方胡麻轮作可持续发展具有重要指导意义。 相似文献
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保护性耕作对黄土高原塬区作物轮作系统磷动态的影响 总被引：4，自引：0，他引：4
在黄土高原塬区,对保护性耕作下小麦-大豆轮作系统的土壤全磷(total phosphorus)、速效磷(available phosphorus)和作物吸磷量进行了动态观测。保护性耕作处理为传统耕作+秸秆覆盖(ts),免耕(nt),免耕+秸秆覆盖(nts),以传统耕作(t)为对照,结果表明,实施保护性耕作10年对轮作系统冬小麦产量没有显著影响,夏播大豆产量对秸秆覆盖有积极响应;免耕处理提高了土壤全磷和速效磷含量,使土壤磷在0～5 cm层次表聚化,土壤磷含量随着保护性耕作时间的延长呈增加趋势, nts和ts 处理下大豆籽粒吸磷量比对照显著提高111%和82%,秸秆覆盖提高了作物对磷的吸收;小麦-大豆轮作有助于提高土壤速效磷含量。结果揭示了黄土高原雨养农业区保护性耕作对土壤-作物系统磷动态的影响,为该系统的磷管理提供了一定的理论指导。 相似文献
15.
岷县不同茬口对当归苗栽生长及抗病性的影响 总被引：2，自引：0，他引：2
当归传统育苗方式造成严重的荒坡地水土流失。在当归道地产区甘肃省岷县通过定向种植小麦、黄芪、马铃薯和当归培育作物茬口基础上,再行当归育苗,育苗期测定苗栽生长动态,育苗结束测定苗栽质量性状及抗病性指标,利用主成分分析确定各指标权重,再结合隶属函数法综合评判,旨在揭示作物茬口对当归苗栽生长发育和抗病性的影响,为筛选适宜当归育苗的农茬口土壤资源提供科学依据和技术参考。结果表明,各茬口条件下当归出苗数和幼苗地上部分生长指标均表现显著差异,小麦茬和黄芪茬当归成苗数和地上生长指标均维持在较高水平,根系发达,生长势强,个体质量优异,根病发病率和病情指数均低,而马铃薯茬和当归重茬苗栽受季节影响较大,随生长期延后当归死苗率提高,易形成老小苗,发病率高达36.7%以上。综合指数大小依次为黄芪茬(0.7840)>小麦茬(0.7816)>当归重茬(0.4731)>马铃薯茬(0.1656)。马铃薯茬死苗率最高,当归重茬根腐病最为严重,说明岷县正茬黄芪和小麦茬口是适宜当归熟地育苗的优异床土资源。 相似文献
16.
陇东旱塬冬小麦复种饲草轮作系统产量和水分利用特征 总被引：1，自引：0，他引：1
在陇东黄土高原大田条件下,连续2年研究了冬小麦-饲草复种轮作系统的干物质产量和水分利用,研究采用的处理有:休闲-冬小麦-箭筈豌豆-冬小麦(F-W-V-W),休闲-冬小麦-饲用油菜-冬小麦(F-W-R-W),饲用油菜-冬小麦-箭筈豌豆-冬小麦(R-W-V-W)和饲用油菜-冬小麦-饲用油菜-冬小麦(R-W-R-W)。结果表明:麦茬复种饲草可比麦茬休闲提高系统生产力27%,蛋白质产量增加1100 kg/hm2, 同时对后茬冬小麦产量无影响。R-W-R-W模式下干物质产量、粗蛋白产量、干物质水分利用效率和蛋白质水分利用效率均最优,分别为30.68 t/hm2、3.25 t/hm2、7.80 kg/(mm·hm2)和0.92 kg/(mm·hm2)(P<0.05)。复种饲用油菜较箭筈豌豆产量高,有效利用了麦茬后降雨量,但箭筈豌豆粗蛋白含量较饲用油菜高22.4%,因此确定麦茬复种模式则需权衡干物质产量与蛋白质产量的需求。 相似文献
17.
黄土高原地区降水较少且季节性分配不均,苜蓿连续种植所导致的深层土壤干燥化问题已经引起普遍关注,苜蓿与粮食作物轮作是恢复苜蓿草地土壤水分、提高粮草种植系统可持续性的有效方式。但是长期轮作对土壤水分环境和水分利用效率的影响仍然缺乏研究,农业生产系统模拟模型（APSIM）具有广泛的适应性,可准确模拟耕作管理对作物系统资源利用的影响。首先根据黄土旱塬区庆阳、长武、镇原3个试验区试验数据验证APSIM模型模拟苜蓿长期连作和苜蓿-小麦轮作系统深层土壤水分和苜蓿产量的可行性,然后设置历时38年的81组轮作情景,评估不同轮作模式对农田深层土壤水分、系统干物质产量、氮素吸收和水分利用效率的影响。结果表明：APSIM模型模拟苜蓿产量的精度较高,模拟结果的决定系数（R2）为0.65,均方误差（RMSE）和平均绝对误差（MAE）分别为0.23 t·hm-2和0.17 t·hm-2,归一化均方误差（NRMSE）为29.2%;模型能够精确模拟长期苜蓿连作和苜蓿轮作小麦农田0~1000 cm的土壤含水量,长期连作模拟结果的R2为0.73,RMSE、MAE及NRMSE分别为0.021 t·hm-2、0.017 t·hm-2和11.7%,轮作系统模拟结果的决定系数为0.83,RMSE、MAE及NRMSE分别为0.024 t·hm-2、0.018 t·hm-2和11.8%。情景模拟结果表明,随着苜蓿在系统中轮作年限的增加,0~1000 cm土壤剖面水分极度缺乏（含水量在0.10~0.15）的区域以400~600 cm土层为起点不断扩大,当苜蓿轮作年限大于12年时,所有轮作周期的处理土壤都出现了大范围水分缺乏。81个情景中12年苜蓿轮作14年小麦（L12W14）、L12W16和L8W16这3个处理的总产量最大;系统吸氮量随着苜蓿加入年限的增加而增加,小麦轮作年限大于10年以后系统吸氮量急剧下降;苜蓿轮作大于8年以后系统水分利用效率随着苜蓿年限的增加而降低。综合考虑土壤水分环境和水分利用效率,建议研究区苜蓿-小麦轮作系统中苜蓿轮作年限为4~6年,小麦轮作年限大于4年。研究结果可为黄土旱塬区苜蓿草地管理及草田轮作实践提供一定的参考。 相似文献
18.
小麦/玉米/大豆套作的产量、氮营养表现及其种间竞争力的评定 总被引：21，自引：0，他引：21
采用多年大田试验研究了小麦-大豆(A1)、小麦-甘薯(A2)、玉米(A3)、小麦/玉米/大豆(A4,麦/玉/豆)和小麦/玉米/甘薯(A5,麦/玉/薯)5种种植模式的生物积累和氮素吸收特性,以探讨麦/玉/豆套作体系的种间竞争力变化规律。试验通过土地当量比(LER)、种间相对竞争力(A)、氮营养竞争比率(NCR)等指标来评定不同套作系统内的作物竞争力。结果表明,麦/玉/豆套作表现出明显的套作优势(LER＞1、Awc<0、Acs>0、NCRwc<0、NCRcs>1),玉米始终占据套作系统的优势生态位,小麦、大豆处于竞争劣势;与A1、A2、A3及A5相比,麦/玉/豆套作提高了各作物在开花期(或吐丝期)与成熟期的籽粒产量与吸氮量和地上部植株的总生物量与总吸氮量;各作物的生物量与吸氮量在处理间的变化规律为套作＞单作、大豆茬口＞甘薯茬口,以A4处理最高。麦/玉/豆套作的全年总经济产出比麦/玉/薯套作平均高28.02%。 相似文献
19.
甘肃省干旱灌区连作马铃薯根际土壤中镰刀菌的变化 总被引：7，自引：0，他引：7
为了深入了解根际土壤镰刀菌分布与马铃薯连作之间的关系,以“大西洋”品种为试材,采用根残体分离法,研究了轮作和连作茬口的马铃薯根际土壤中镰刀菌的变化趋势。结果表明,在不同茬口根际土壤中共分离到8个种的镰刀菌,玉米-马铃薯轮作茬口的优势种为再育镰孢,分离频率为23.34%;连作1～3年茬口的优势种均为茄病镰孢,分离频率分别为30.78%,37.70%和45.48%。随着连作年限的增加,马铃薯根际土壤镰刀菌数量呈上升趋势,但不同菌种的数量变化趋势各异,尖孢镰孢、茄病镰孢呈上升趋势,黄色镰孢、再育镰孢呈下降趋势,木贼镰孢变化较为平稳。 相似文献
20.
对70份当地和引入紫云英种质资源在豫南地区种植的表型性状和结实特征进行研究,结果表明,供试紫云英均可在豫南地区完成扩繁,19个调查性状的变异系数(CV)介于1.3%~73.2%,其中冠层面积(CV=45.9%~73.2%)、始荚高度(CV=46.0%~52.9%)、生殖分枝数和生殖分枝比率(CV=34.6%~48.4%)、二级分枝数(CV=41.2%~41.3%)、返青期株高(CV=30.2%~39.2%)、种子产量(CV=24.4%~35.7%)变异性较高。信紫1号、XYHY-1等6个当地资源在越冬期和返青期叶片呈现紫红色。种子产量与返青期株高、盛花期株高、越冬期冠层大小、始荚高度、结荚层数、种子千粒重显著正相关;种子千粒重与返青期株高、盛花期株高、越冬期冠层大小、始荚高度、结荚层数、生殖分枝比率显著正相关,与出苗至盛花期天数、全氮和全磷含量显著负相关。引入资源平均种子产量为1015.5 kg·hm^(-2),当地资源平均种子产量为1096.5 kg·hm^(-2)。与冬油菜和冬小麦相比,大部分紫云英种质资源在豫南地区繁种具有较高的经济效益,适合移栽稻接茬。 相似文献