包膜控释尿素对马铃薯生长发育及产量的影响

试验开展了包膜控释尿素对马铃薯生育期株高、主茎数、茎粗、叶面积指数、叶绿素含量、单株结薯数、单株产量、商品薯率和产量的影响研究。结果表明,与施用普通尿素相比,包膜控释尿素施用量为普通尿素的80%时,在所有调查指标方面均表现最好,且商品薯率达到87.3%,折合产量为2 646 kg/667m2,较不施氮肥增产33.4%,较普通氮肥增产8.7%。     

土壤酸碱度对甜菜生长发育及产量的影响

１９９８－１９９９年进行了甜菜酸性土壤改良试验,结果表明,施用熟石灰可有效地中和土壤酸度,补充甜菜所需要的钙,在１５ｃｍ耕层内增施熟石灰３１．３ｇ／ｍ＾２,Ｐ珂提高０．１。土壤ＰＨ值越接近中性越有利于甜菜生长,土壤越酸,土壤越酸,施熟石灰增产效果越显著。     

不同形态氮素对甜菜生长发育的影响

论述了不同形态氮素对甜菜硝酸还原酶活性、谷氨酰胺合成酶活性及蔗糖合成酶活性的影响,并在影响生理生化过程的基础上,对氮素形态和甜菜生长发育及产质量的相关性进行了分析,提出了不同形态氮素配合施用是提高甜菜保护酶系统活性及其抗逆性的有效途径。     

新型尿素缓释剂对甜菜产质量的影响

探讨了在甜菜栽培中施用新型尿素缓释剂对其产质量的影响。试验结果表明:尿素缓释剂通过对土壤脲酶活性的抑制作用,减少了尿素氮的损失,提高了尿素的肥效,促进了甜菜的生长发育,提高了甜菜产质量,经济效益显著。     

磷酸二铵施用部位对大豆产量的影响

采用磷酸二铵进行施用部位效应研究,三年试验表明:大豆施底肥(磷酸二铵施于种下10cm)比施口肥(施于种下1cm)增产9.5—23.2％;施口肥比不施肥增产11.2％。     

灌水量对滴灌甜菜生长发育及产质量的影响

为了明确膜下滴灌甜菜的需水规律,指导生产科学灌溉,开展灌水量对滴灌甜菜生长发育及产质量的影响研究.结果表明灌水量对甜菜的叶片数影响不大但对甜菜的叶丛高度有明显影响,随着灌水量的增加叶丛高度也增高,在灌水量为360m3/667m2时甜菜叶丛最高.甜菜块根膨大和产质量受灌水量影响显著,在灌水量为120m3/667m2时甜菜的块根直径、根体长度、产量、含糖率及产糖量都处于较低水平,随着灌水量的增加,甜菜的块根大小、产量和含糖率都呈现出上升趋势,但当灌水量大于360m3/667m2时甜菜的产量略有减少,含糖率急剧下降.因此,在玛纳斯产区膜下滴灌甜菜灌水量控制在360m3/667m2左右较为合理.     

缓释尿素对超级杂交稻Y两优1号生长发育及氮肥利用率的影响

在大田试验条件下,研究了硫包衣尿素(SCU)不同用量对超级杂交中稻Y两优1号生长发育、产量及氮肥利用率的影响。结果表明,SCU用量在0~270 kg/hm2(纯氮)范围内,随施氮量的增加,最高苗数、有效穗数、穗平总粒数和生物产量均增加,而结实率呈下降趋势;其用量达到180 kg/hm2时产量最高(11.98 t/hm2),氮肥农学利用率最大(21.2 kg/kg),氮肥吸收利用率也在50%以上。初步认为SCU用量180kg/hm2(折纯氮)是其在超级杂交中稻Y两优1号生产中的适宜用量。     

化肥减施下生物有机肥对甜菜生长发育及产质量的影响

为了筛选内蒙古地区甜菜减施化肥下配施生物有机肥的最佳用量,以常规施甜菜专用化肥(900 kg/hm2)为对照(L0),在化肥施用量为450 kg/hm2条件下,设置5个生物有机肥施用量处理L1(1500 kg/hm2)、L2(3000 kg/hm2)、L3(4500 kg/hm2)、L4(6000 kg/hm2)、L5...     

盐胁迫对滨海稻区粳稻生长发育及产量的影响

为探明不同梯度盐胁迫对滨海稻区粳稻生长发育和产量的影响,利用盆栽的方式人为设置不同梯度盐胁迫(1.82‰、2.73‰、3.64‰、4.55‰),以5个水稻品种为材料,研究不同梯度盐胁迫对粳稻生长发育和产量的效应。结果表明:随着盐分的增高,水稻秧苗成活率降低,盐粳219的秧苗成活率最高。盐胁迫下水稻茎蘖峰值的出现略有延迟,延后1周至4周不等。株高、成熟期水稻单盆干物质积累量随着盐分的增高逐渐降低。盐粳252、盐粳269、盐粳939齐穗期叶片SPAD值与含氮量随着盐分的增高逐渐减少,盐丰47、盐粳219齐穗期叶片SPAD值与含氮量在1.75‰～3.50‰范围内随着盐分的增高逐渐减少,在4.375‰胁迫下略有上升。在1.82‰～4.55‰的盐胁迫范围内,各品种水稻产量随盐分的增高逐渐降低,5个水稻品种单盆产量总体平均降低35.36%。相关分析表明,盐胁迫主要通过显著降低收获穗数和千粒重,进而导致水稻产量降低的。     

磁场对水稻生长发育及产量的影响

用一定强度的磁场处理水稻干种子,能使水稻生物学效应发生一系列的变化。本试验在研究不同磁强处理水稻最佳剂量的基础上,探讨了在1000MT×20分钟磁强处理下,不同水稻品种的增产效果,为水稻高产开僻了一条新途径。     

内蒙古固阳冷凉干旱区甜菜营养生长特性的研究

通过田间观察和定期生长分析,明确了冷凉干旱区采用地膜覆盖、灌溉栽培甜菜的各营养生长期的根、叶生长和糖分积累特点,讨论了甜菜生长中心的转移推迟和糖分积累期生长速率、净同化率大幅度降低的原因,提出提早间、定苗和通过水肥调控促进甜菜早发,加速生长中心转移,缩短叶丛快速生长期和改善水分状况,促进块根增长和糖分积累的措施。     

The effects of nitrogen supply and stem density on leaf attributes and stem branching in potato (Solanum tuberosum L.)

Summary The interaction between nitrogen supply and stem density on leaf attributes and branching was studied in two field experiments. Stem densities included 8, 16, 24, 32 and 40 stems m⁻². The low-N treatments received 5 or 10 g m⁻² nitrogen, and the high-N treatments 20 or 25 g m⁻². The sizes of mature individual leaves on the main stem declined with increase in stem density and were larger for greater N supply, with additive effects of nitrogen and stem density. The specific leaf area was not affected by nitrogen supply and increased with stem density (range of values: 210 to 310 cm² g⁻¹). The leaf weight ratio was not affected by the treatments. At 8 and 16 stems m⁻² basal branches contributed substantially to the total leaf area per stem: at 24 stems m⁻² and higher densities the development of basal branches was negligible. Leaf area on apical branches was always smaller for higher plant densities and lower rates of N supply.     

叶面喷施木醋液对油菜苗期生长发育的影响

为充分利用生物炭制成过程中产生的木醋液,研究其促生作用,通过油菜盆栽试验,研究叶面喷施杨木的木醋液对油菜苗期发育的影响。木醋液浓度为稀释600、500、400、300、200、150、100、50、10倍,共9个处理,以喷施清水为对照。设置3月14日、4月4日两个播期,在两个播期的油菜幼苗分别达到三叶、八叶期时,于同一天进行叶面处理。结果表明,于油菜三叶、八叶期叶面喷施稀释300～500 倍的木醋液可提高油菜的根干3.04%～41.98%,茎干重35.74%～68.27%,叶干重19.80%～55.90%,植株总干重27.14%～57.02%;同时显著提高了油菜的株高和根颈粗,以及最大叶长、最大叶宽、叶面积、比叶重,其中以喷施稀释400倍木醋液的促进作用最强,其叶面积可比对照增加50.97%～85.53%。稀释10～50倍的高浓度木醋液则对油菜生长具有明显抑制作用。不同喷施时期相比较,以三叶期喷施处理对根系、茎秆和叶片增长效应更明显,八叶期施用对根的促进作用相对减弱。比较植株根冠比的变化发现,木醋液对油菜生长产生促进作用时,会降低根冠比值,即地上部茎叶的反应更强烈。综上所述,三叶期和八叶期喷施稀释300～500倍的木醋液可显著提高油菜的株高、根颈粗、叶面积、比叶重,显著增加油菜的生物量。一般以稀释400倍浓度的木醋液在三叶期施用效应更好。     

Effects of amylose and wheat bran on the levels of blood serum urea nitrogen (BUN), other blood parameters,growth and fecal characteristics in rats

A basal diet (containing 20% soybean protein isolate) was supplemented with limiting amino acids (AA, methionine, threonine and tryptophan); wheat bran (WB, 24.3%); amylose (AM, 10%) or a combination of AA and WB or AM to investigate their effects on the levels of blood serum urea nitrogen (BUN), other blood parameters, growth and fecal characteristics in young rats. After 3 weeks feeding, supplementation of the basal diet with AA or WB resulted in improved growth (gain/food ratio) while the addition of AM had no effect on rat growth. Addition of WB to the basal diet had no effect on BUN while the addition of AA and AM caused about 20 and 12% reduction in BUN values, respectively. Rats fed the AA-AM diet had the lowest BUN values (42% lower than those fed the basal diet). Fresh volume, fresh weight, moisture and dry weight of feces in rats fed the WB diets were about four to five fold higher than in those fed the AM diets. The results suggested that BUN may not be a good predictor of growth and protein quality in diets containing AM or a source of dietary fiber (WB).     

The effects of nitrogen and iron fertilization on growth,yield and fertilizer use efficiency of soybean in a Mediterranean-type soil

Poor seed yield of soybean in Mediterranean-type environments may result from insufficient iron (Fe) uptake and poor biological nitrogen (N) fixation due to high bicarbonate and pH in soils. This study was conducted to evaluate the effects of N and Fe fertilization on growth and yield of double cropped soybean (cv. SA 88, MG III) in a Mediterranean-type environment in Turkey during 2003 and 2004. The soil of the experimental plots was a Vertisol with 176 g CaCO₃ kg⁻¹ and pH 7.7 and 17 g organic matter kg⁻¹ soil. Soybean seeds were inoculated prior to planting with commercial peat inoculants. N fertilizer rates were 0, 40, 80, and 120 kg N ha⁻¹ of which half was applied before planting and the other half at full blooming stage (R2). Fe fertilizer rates were 0, 200 and 400 g Fe EDTA (5.5% Fe and 2% EDTA) ha⁻¹. It was sprayed as two equal portions at two trifoliate (V2) and at five trifoliate stages (V5). Plants were sampled at flower initiation (R1), at full pod (R4) and at full seed (R6) stages. Application of starter N increased biomass and leaf area index at R1 stage whereas Fe fertilization did not affect early growth parameters. N application continued to have a positive effect on growth parameters at later stages and on seed yield. Fe fertilization increased growth parameters at R4 and R6 stages, and final seed yield in both years. This study demonstrated an interactive effect of N and Fe fertilization on growth and yield of soybean in the soil having high bicarbonate and pH. There was a positive interaction between N and Fe at the N rates up to 80 kg N ha⁻¹. However, further increase in N rate produced a negative interaction. Fertilization of soybean with 80 kg N ha⁻¹ and 400 g Fe ha⁻¹ resulted in the highest seed yield in both years. We concluded that application of starter and top dressed N in combination with two split FeEDTA fertilization can be beneficial to improve early growth and final yield of inoculated soybean in Mediterranean-type soils.     

Plant growth strategies of Thymus vulgaris L. in response to population density

Thymus vulgaris L., known as common thyme, is a perennial subshrub native to the Mediterranean region. The use of the extracts and herb of thyme plants as antibacterial, antioxidant, natural food preservative and in cosmetic industry has increased the economic importance of this medicinal crop worldwide. Agricultural practices have an influence on growth and yield of thyme plants. Therefore, an experiment was undertaken to determine the effects of three intra-row spacing (15, 30 and 45 cm) and four harvesting times (vegetative, beginning of blooming, full blooming and fruit set) on plant growth and herbage biomass of thyme in 2007 in the research farm of Shoubak University College in the southern part of Jordan. The experiment was a split plot in randomized complete block design with four replicates. Apart from the experiment in 2007, measurements taken on the 15th of November in 2008 were treated as an independent experiment irrespective of harvesting stage. The effects of spacing were not significant for all the parameters measured in 2007. Intra-row spacing in 2008 had significant effects (P < 0.05) on plant height, canopy diameter, herbage fresh and dry weight and number of leaves on long shoots. Its effect on dry weight of shoots, fresh and dry weight of long shoots, number of long shoots, root depth, leaf area and specific leaf area was very significant (P < 0.01). Results of this study indicated that thyme plants grown using 15 cm planting space and harvested at the fruit set stage in 2007 had the highest fresh and dry weight of shoots. The highest dry weight of shoots, herbage fresh and dry weight was also obtained in 2008 in 15 cm spacing. Closer spacing resulted in significantly taller plants that exhibited higher shoot:root ratio and, therefore, plants grown using 15 cm intra-row spacing had a better use of light and accumulated more biomass compared to plants in wider spacing. The differentiation between long shoots and short shoots throughout plant development in 2007 suggests a specialization in carbon gain along different times in the growing season. Swings observed for shoot:root ratio, leaf area and specific leaf area were related to thyme growth. The decrease in specific leaf area between vegetative and full bloom stage indicated that leaves became thicker as part of an adaptive mechanism to the surrounding environment. Information obtained from growth parameters, leaf area and specific leaf area in particular, could be related to essential oil production in leaves of thyme plants.     

The effects of autumn closing date on sward leaf area index and herbage mass during the winter period

The provision of grass for early spring grazing in Ireland is critical for spring calving grass‐based milk production systems. This experiment investigated the effect of a range of autumn closing dates (CD), on herbage mass (kg DM ha^?1), leaf area index (LAI) and tiller density (m^?2) during winter and early spring. Thirty‐six grazing paddocks, closed from 23 September to 1 December 2007, were grouped to create five mean CD treatments – 29 September, 13 October, 27 October, 10 November, 24 November. Herbage mass, tiller density and LAI were measured every 3 weeks from 28 November 2007 to 20 February 2008; additionally, herbage mass was measured prior to initial spring grazing and tiller density was measured intermittently until September 2008. Delaying CD until November significantly (P < 0·05) reduced herbage mass (by approximately 500 kg DM ha^?1) and LAI (by approximately 0·86 units) in mid‐February. On average, 35% of herbage mass present on swards on 20 February was grown between 28 November and 30 January. LAI was positively correlated with herbage mass (R² = 0·78). Herbage mass increased by approximately 1000 kg DM ha^?1 as spring grazing was delayed from February to April. Tiller density increased from November to February, although it did fluctuate, and it was greatest in April (9930 m^?2). This experiment concludes that in the south of Ireland adequate herbage mass for grazing in early spring can be achieved by delaying closing to early mid‐October; swards required for grazing after mid‐March can be closed during November.     

低氮条件下密度对红壤旱地秋芝麻产量和叶面积指数的影响

为了探索低氮条件下红壤旱地秋芝麻高产栽培的适宜种植密度,2016年-2017年在进贤县和南昌县开展试验,研究6个密度（D1-15.0、D2-22.5、D3-30.0、D4-37.5、D5-45.0和D6-52.5 株/m2）对秋芝麻产量构成因素、产量和叶面积指数的影响。结果表明：2017年南昌县试验点D1和D2的单株蒴果数较D4显著增加18.32%和20.27%,其它处理的每蒴粒数较D3显著增加15.92%~25.04%;随着密度的增加秋芝麻产量呈现先增后减再增的趋势,2016年进贤点密度为D6时产量较D1显著增加40.78%,2017年进贤点为D2和D6时产量较D3显著增加18.00%和16.74%,2017年南昌点为D2、D5 和D6 的产量较D3 显著增加32.86%~44.15%。D2、D5、D6 的产量平均值较D1 显著增加20.66%~26.82%。叶面积指数随着种植密度的增加而增加,同时随着芝麻生长发育都表现为先增后减的趋势。因此,秋芝麻适宜密度应控制在22.5株/m2或45.0~52.5株/m2,才能够构建合理冠层,达到高产效果。     

Analysis of yield-attributing traits for high-yielding wheat lines in southwestern Japan

Development of wheat cultivars that achieve high yields despite the short growing season is essential for increasing wheat production in southwestern Japan. The objectives of this study were to assess the genetic progress in grain yield and to clarify yield-attributing traits of high-yielding wheat lines in southwestern Japan. We conducted field experiments for two growing seasons (2012–2013 and 2013–2014) using three commercial wheat cultivars (Shiroganekomugi, Chikugoizumi, and Iwainodaichi) and four high-yielding wheat lines including Hakei W1380 developed in southwestern Japan. In an ancillary field experiment, we compared a commercial cultivar, Shiroganekomugi, and a high-yielding line, Hakei W1380, in the 2014–2015 season. Across the two seasons, grain yield of high-yielding lines was generally higher than commercial cultivars. Hakei W1380 achieved the highest grain yield across the two seasons, and successfully produced more than 900 g m^?2 in the 2013–2014 season. Correlation analysis showed that recent yield progress of wheat lines in southwestern Japan was derived from enhanced biomass production and grain number m^?2. Larger numbers of grains m^?2 in high-yielding lines than in commercial cultivars were associated with higher crop growth rate at the pre-anthesis stage, and therefore higher spike dry weight m^?2 at anthesis. Genotypic differences in crop growth rate from jointing to anthesis resulted mainly from differences in leaf area index. These results indicate that further improvements in grain yield in southwestern Japan could be achieved by increasing the amount of radiation intercepted at the pre-anthesis stage and grain number m^?2.