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.     

成龄油棕园林下间作生姜栽培技术与效益分析

介绍成龄油棕园林下间作生姜的栽培技术方法，并对间作效益进行分析，分析表明，间作效益的大小需考虑油棕园的荫蔽度。     

麦棉套种对预留棉行光合有效辐射的影响

对东西行向、预留棉行为１００ｃｍ的三二式麦棉套种方式研究表明，在小麦抽穗后的麦棉共生期间，预留棉行上的平均光合有效辐射仅为一熟棉田的５０％～８０％，株高低和叶片枯黄时光照削弱较小；在麦棉间距相同的情况下，北行棉花接受的ＰＰＦＤ较多，而正午前后南行棉花易受荫蔽，南行棉花适当北移，保持麦棉间距在３０ｃｍ以上，降低小麦群体株高，防止小麦旺长，起垄种棉，都有利于棉花生长发育。     

小麦收获期对麦套棉田捕食性天敌和棉花苗蚜的影响

2004-2005年在冀南棉区研究了小麦收获期对麦套棉田中捕食性天敌和棉花苗蚜的影响。小麦收获期共设3个水平,分别是6月5日、6月10日和6月15日收获小麦。结果表明:2004年3个时期收获小麦对棉田的益害比(天敌和棉蚜的比值)无显著影响(t>0.05);2005年6月5日收获小麦,显著增加了棉田的益害比(t<0.05),6月10日和6月15日收获小麦对棉田的益害比无显著影响(t>0.05)。说明在麦套棉田中,麦田天敌到棉田的有效转移受麦蚜-天敌-棉蚜三者发生高峰期的影响,不同年份天敌的转移情况有所不同。麦蚜发生高峰期早则小麦天敌向棉田转移早,并能有效控制苗期蚜虫的危害,在麦熟期收获小麦,对棉田天敌的数量影响不大;反之,若麦蚜发生高峰期晚,麦田天敌发生期也会相应延后,在麦熟期收获小麦则会引起棉田天敌的增加。因此,棉田天敌数量变化受小麦收获期的影响,但与麦蚜和麦田天敌的发生动态有直接关系。     

麦棉套种共生期土壤水分对冬小麦产量和品质的影响

在3-1式和4-2式2种麦棉套种方式的条件下,在防雨棚内采用小区试验研究了麦棉共生期间土壤水分条件对冬小麦产量和品质的影响。试验结果表明,麦棉共生期间土壤水分显著影响了冬小麦的产量和品质。冬小麦籽粒中含水率、沉降值、蛋白质随土壤水分增加而降低;较低的土壤含水量处理小麦籽粒蛋白质含量增加;2种套种方式均以70%土壤含水量处理的冬小麦产量最高,土壤水分升高或下降都会降低产量;3-1套种方式小麦籽粒蛋白质和湿面筋含量显著高于4-2式。     

Recent Advances in the Enhancement of Agroecosystem Services and Functioning by Cotton-based Intercropping Systems

Cotton-based intercropping systems are one of modern agriculture farming systems aiming at improving overall economic profitability of cotton field, which not only release the competition for land between other crops and cotton and increase growing area and yield of both crops, but also represent a mechanistic approach to reconciling crop production and biodiversity conservation. Recently, cotton-based intercropping systems have been widely focused and applied. Here, we reviewed the potential of cotton-based intercropping systems to reinforce agroecosystem services and functioning, including promoted plant biodiversity, improved overall productivity and economic profits, increased light use efficiency, improved cotton quality, reduced pest and disease occurrence, and suppressed weed growth. Further, the underlying mechanisms behind the enhancement of agroecosystem services and functioning by cotton-based intercropping systems through niche complementarity, interspecific facilitation, and allelopathy between intercropped species were summarized in the paper. Finally, the research prospects were also pointed out.     

Cropping systems for the management of phytonematodes

Damage caused by nematodes is one of the limiting factors in crop production. Traditional nematode management is based on the use of crop rotations, resistant cultivars, nematicides, or combinations of these methods. For a crop like peanut (Arachis hypogaea), cultivars resistant to root-knot nematodes are not available. There are soybean (Glycine max) cultivars resistant to some of the species of root-knot nematodes (Meloidogyne spp.); however, most fields have nematode infestations composed of mixtures of species. Research at Auburn has shown that tropical crops can be used effectively in rotation to manage nematode problems. Rotations with American jointvetch (Aeschynomene americana), castor (Ricinus communis), hairy indigo (Indigofera hirsuta), partridge pea (Cassia fasciculata), sesame (Sesamum indicum), and velvetbean (Mucuna deeringiana) have resulted in good nematode control and increased yields of peanut and soybean. Some crops (castor, sesame) are considered ‘active’ in that they produce compounds that are nematicidal, whereas others (e.g. corn, sorghum) are simply non-host, that is, ‘passive’.