插条粗度和萌芽度对降香黄檀扦插成活率的影响

在江门市林科所苗圃选择不同粗细度、不同萌芽度的降香黄檀插条进行扦插繁殖试验,每10 d进行1次成活率调查。结果表明:插条的萌芽度和粗细度均极显著影响扦插的成活率,萌芽度和粗细度的交互作用对扦插的成活率也有极显著影响;未萌芽插条扦插成活率明极显高于已萌芽插条的扦插成活率;3种粗细度的枝条中以粗细度为0.7~1.2 cm的插条扦插成活率最高;在枝条萌芽度及粗细度交互作用下,粗细度为0.7~1.2 cm的未萌芽插条扦插成活率最高,粗细度小于0.7 cm的已萌芽插条扦插成活率最低。     

油草混播种类对油菜生产和草地生产性能的影响

为筛选与门源油菜混播效益最高的牧草种类,解决油菜连作障碍问题,提高青藏高原高海拔区土地的生产能力,本研究采用油菜混播箭筈豌豆、青稞和燕麦的方式,分时段取样,探究了油菜混播不同牧草对在不同时段牧草自身生产能力的影响,并通过土地当量比判断各混播组合的优劣。研究表明油菜-燕麦混播处理在7月6日时表现干重最高,单位面积达174.48 g；在7月21日表现为鲜重和鲜干比最高,在8月15日时表现为株高显著高于单作油菜(p＜0.05),较单作油菜高97.02%；鲜重最高,达2817.00 g。在9月11日,油菜-青稞和油菜-燕麦混播处理的株高显著高于单作油菜(p＜0.05),分别较单作油菜高64.33%和99.68%,以油菜-青稞混播处理的干重最高,达589.00 g,较单作油菜处理高147.51%。油菜-箭筈豌豆混播和油菜-燕麦混播有产量优势,油菜-燕麦混播的土地当量比最高,为1.11,土地利用效果最好。     

Modelling soil erodibility in mountain rangelands of southern Kyrgyzstan

Soil erosion in mountain rangelands in Kyrgyzstan is an emerging problem due to vegetation loss caused by overgrazing. It is further exacerbated by mountain terrain and high precipitation values in Fergana range in the south of Kyrgyzstan. The main objective of this study was to map soil erodibility in the mountainous rangelands of Kyrgyzstan. The results of this effort are expected to contribute to the development of soil erodibility modelling approaches for mountainous areas. In this study, we mapped soil erodibility at two sites, both representing grazing rangelands in the mountains of Kyrgyzstan and having potentially different levels of grazing pressure. We collected a total of 232 soil samples evenly distributed in geographical space and feature space. Then we analyzed the samples in laboratory for grain size distribution and calculated soil erodibility values from these data using the Revised Universal Soil Loss Equation (RUSLE) K-factor formula. After that, we derived different terrain indices and ratios of frequency bands from ASTER GDEM and LANDSAT images to use as auxiliary data because they are among the main soil forming factors and widely used for prediction of various soil properties. Soil erodibility was significantly correlated with channel network base level (geographically extrapolated altitude of water channels), remotely sensed indices of short-wave infrared spectral bands, exposition, and slope degree. We applied multiple regression analysis to predict soil erodibility from spatially explicit terrain and remotely sensed indices. The final soil erodibility model was developed using the spatially explicit predictors and the regression equation and then improved by adding the residuals. The spatial resolution of the model was 30 m, and the estimated mean adjusted coefficient of determination was 0.47. The two sites indicated different estimated and predicted means of soil erodibility values (0.035 and 0.039) with a 0.05 significance level, which is attributed mainly to the considerable difference in elevation.     

Optimisation of fertiliser rates in crop production against energy use indicators

Optimising mineral nitrogen (N) use in crop production is inevitable target as mineral fertilisers reflect one of the highest inputs both in terms of economy and energy. The aim of the study was to compare the relationship between the rate of N fertiliser application and different measures of energy parameters exemplary data for spring-wheat in boreal climate condition in Estonia in 2006–2010. The effect of mineral N with rates 0, 40, 80, 120 and 160 kg N ha⁻¹ was studied on the background of composted cow manure and without organic fertilisers. Univalent parameters, energy gain (EG) (energy output − energy input) and energy ratio (ER) (energy output/energy input) were calculated. To aggregate parameters with different units (ER and EG) we proposed two standardisation approaches for combined indices. ER maximisation gave both organic fertilisation background optimum N norms significantly lower than EG (p < 0.05) optimisation. Both the new combined indices gave optimum N norms in between the rate of ER an EG. Composted cow manure background did not affect mineral N optimisation significantly. We suggest optimisation of mineral N according to bi-dimensional parameters as they capture important features of production efficiency and are more objective using as advisory tool for sustainable production systems.     

不同外源激素对糜子成穗及产量的影响

研究不同种类外源激素对糜子成穗及产量的影响。用5种外源激素在糜子3~4叶期喷施,连续处理2次,喷清水为对照。记录糜子苗期基本苗数、拔节期总茎数、成熟期穗数等性状,用统计软件SPSS 17.0进行统计分析。结果表明,施用脱落酸（ABA）能够显著降低糜子的分蘖数,施用赤霉素（GA₃）、吲哚乙酸（IAA）、矮壮素（CCC）也能减少糜子分蘖数,但是与对照差异不显著,施用多效唑（PP₃₃₃）对糜子分蘖数没有明显影响;施用GA₃、IAA、CCC能够增加分蘖穗数,而ABA、PP₃₃₃降低分蘖穗数;各处理分蘖成穗率都较对照高,ABA处理分蘖成穗率为最高达到25.20%;ABA处理主茎穗占比较对照增加,分蘖穗占比降低;GA₃、IAA、CCC处理主茎穗占比相对于对照降低,分蘖穗占比增加,PP₃₃₃处理与对照相近;5种外源激素对糜子产量的影响差异显著,施用ABA产量最高,可能与主茎穗占比高和分蘖成穗率高有关系。在糜子3~4叶期喷施5种外源激素,对糜子有显著作用的是ABA,主要表现在ABA能够降低糜子分蘖数,保证了主茎的成穗数量,增加了分蘖成穗率,从而提高了糜子产量。     

旱地燕麦间作对土壤酶活性、微生物含量及产量的影响

本文通过研究内蒙古旱作区禾本科、豆科及茄科间作对土壤生物性状的影响，旨在揭示燕麦（Avena sativa Linn）与不同作物间作及其单作在土壤酶活性、微生物量及土地当量比（LER）等方面的优势机理。本试验设置燕麦、黑豆（Glycinemax（L.）merr）、苜蓿（Medicago sativa）、马铃薯（Solanum tuberosum L）单作和黑豆间作燕麦、苜蓿间作燕麦、马铃薯间作燕麦共7个处理，探讨各处理对上述各指标的影响。结果表明：燕麦间作黑豆土地当量比最高，2015年和2016年分别为1.62和1.65。燕麦间作黑豆土壤脲酶活性和蔗糖酶活性较苜蓿间作燕麦、马铃薯间作燕麦显著提高了5.00%~51.61%和5.73%~52.29%。2015年和2016年播种后75 d苜蓿间作燕麦土壤过氧化氢酶活性显著高于黑豆间作燕麦，分别提高了29.47%和40.56%。黑豆间作燕麦对比其他两间作处理土壤微生物的生物量碳、氮含量分别显著提高了2.70%~17.89%和11.36%~26.47%，土壤脲酶活性提高了1.51%~55.22%，蔗糖酶活性提高了5.73%~52.29%，是该地区最优的间作模式。     

Maize/peanut intercropping increases photosynthetic characteristics, ~(13)C-photosynthate distribution,and grain yield of summer maize

Intercropping is used widely by smallholder farmers in developing countries to increase land productivity and profitability. We conducted a maize/peanut intercropping experiment in the 2015 and 2016 growing seasons in Shandong, China. Treatments included sole maize(SM), sole peanut(SP), and an intercrop consisting of four rows of maize and six rows of peanut(IM and IP). The results showed that the intercropping system had yield advantages based on the land equivalent ratio(LER) values of 1.15 and 1.16 in the two years, respectively. Averaged over the two years, the yield of maize in the intercropping was increased by 61.05% compared to that in SM, while the pod yield of peanut was decreased by 31.80% compared to SP. Maize was the superior competitor when intercropped with peanut, and its productivity dominated the yield of the intercropping system in our study. The increased yield was due to a higher kernel number per ear(KNE). Intercropping increased the light transmission ratio(LTR) of the ear layer in the maize canopy, the active photosynthetic duration(APD), and the harvest index(HI) compared to SM. In addition, intercropping promoted the ratio of dry matter accumulation after silking and the distribution of ~(13) C-photosynthates to grain compared to SM. In conclusion, maize/peanut intercropping demonstrated the potential to improve the light condition of maize, achieving enhanced photosynthetic characteristics that improved female spike differentiation, reduced barrenness, and increased KNE. Moreover, dry matter accumulation and ~(13) C-photosynthates distribution to grain of intercropped maize were improved, and a higher grain yield was ultimately obtained.     

黏虫蛹性别的快速鉴别方法

根据黏虫Mythimna separata(Walker)蛹生殖孔的位置、腹部腹节的外部形态学特征、生殖孔(产卵孔)至排泄孔之间的距离,快速、准确鉴别黏虫蛹性别。雌蛹第8腹节腹面中央的生殖孔与第9腹节的产卵孔连接形成一纵裂缝,裂缝两侧平坦,无突起。生殖孔下端与第9腹节的前缘连接、产卵孔下端与第10腹节的前缘连接,形成2个明显的"人"字纹。雄蛹第8腹节无纵裂缝,在第9腹节腹面中央的生殖孔呈现的纵裂缝连接第10腹节,裂缝两边各有一个半圆形瘤状突起。雌雄蛹排泄孔均在第10腹节腹面,雌蛹产卵孔下端至排泄孔上端之间的距离为(400.85±151.10)μm,雄蛹生殖孔下端至排泄孔上端之间的距离为(178.21±93.59)μm,约为雌蛹相应距离的一半。采用该方法观察的270头羽化蛹的性别鉴别准确率100%。该方法对于快速鉴别黏虫蛹的性别、开展黏虫相关的生物学研究以及预测预报等具有重要的参考价值。