保水剂在陕西关中灌区农业生产中的应用研究

针对陕西关中灌区面临耕地面积减少和灌溉水资源匮乏的现状,发展节水灌溉已成为必要举措。通过对保水剂施加在塿土中的室内土壤机理变化结果,以及不同作物在施加保水剂的塿土盆栽和大田试验应用效果的分析,可以看出,保水剂施加到关中塿土中,能够增强塿土保水持肥改土的能力,促进作物的生长,改善作物的性状,增加作物的产量,提高作物的品质,有力地缓解关中灌区的耕地压力,提高灌区灌溉水利用效率,减少灌溉水资源的缺口,达到节水增效的目的,从而推动关中灌区农业生产发展,保障区域粮食安全。     

腐植酸保水剂的制备及性能测试

[目的]为了提供农林用的优质保水保肥材料。[方法]以丙烯酸-丙烯酰胺和腐植酸为原料,采用水溶液聚合法合成聚(丙烯酸-丙烯酰胺-腐植酸)型多功能复合保水剂,利用红外光谱和吸水倍率对所制备的保水剂进行表征。[结果]制备的腐植酸保水剂具有良好的耐温耐盐性,对蒸馏水的吸收倍率为1 180 g/g,达50%饱和吸水量的时间是6.5 min,达90%饱和吸水量的时间是22.0 min,对0.9%盐水吸收倍率为110 g/g;红外光谱分析表明,腐植酸参与聚合反应,与高吸水树脂接枝到一起,所制备的腐植酸型保水剂是化学键合型腐植酸保水剂。[结论]该工艺制备的保水保肥剂能够很好地适用于农林。     

秸秆腐熟剂的应用效果

[目的]为了验证秸秆腐熟剂产品在秸秆还田模式下的应用效果。[方法]采用秸秆腐熟剂的田间对比试验。[结果]秸秆腐熟剂能够加快稻草腐熟。[结论]秸杆腐熟剂对有机质提升有明显的促进作用,在产量对比上表现为显著。     

不同拌种剂对连作花生病害发生及产量的影响

在大田条件下,研究了8种不同的拌种剂对连作花生病害发生及产量的影响。试验结果表明:用戊唑醇、醚菌酯、百菌清进行拌种处理可以明显地提高花生的出苗率和成苗率,且对花生叶斑病的发生有较好的控制效果;多抗霉素、戊唑醇、醚菌酯处理对花生锈病的发生有较好的控制效果;百菌清、苯醚甲环唑、醚菌酯处理对花生的增产效果较好。     

草莓炭疽病的生物防治研究

[目的]研究草莓炭疽病（Colletotrichum fragariae）的生物防治方法。[方法]采用菌丝生长抑制法测定枯草芽孢杆菌（ Bacillus subtilis）（BS）和蛇床子素（SC）对草莓炭疽病菌的室内抑菌活性,并进行田间防治试验。[结果]室内测定结果表明,BS和 SC对草莓炭疽病菌菌丝生长都有极强的抑菌活性,其 EC50值分别为0.0075和1.0630 ml/L。田间防治结果显示,无论在避雨或露天条件下,BS（用量600-750 g/hm2）和25%咪鲜胺 EC （用量600 ml/hm2）,在防治3次后7和14天的防治效果均达76%以上,但两药剂与SC（用量1800-2700 ml/hm2）的田间防治效果间有极显著差异（P〈0.01）。[结论]枯草芽孢杆菌可以用于草莓炭疽病的防控。     

化学药物GSC不同浓度对白菜型冬油菜主要性状的影响

以白菜型冬油菜品种鉴94为材料,研究化学药物GSC的不同浓度对白菜型冬油菜主要性状的影响。结果表明,GSC处理两次后,导致植株生长势变弱,而对结实力无显著影响;对油菜花冠和花瓣的生长有一定抑制作用,随着化学药物浓度的增加,花冠直径和花瓣面积呈减小趋势,雄蕊长度逐渐缩短,雌蕊无显著变化,T7浓度处理(第一次0.5 mg·L^-1和第二次0.6 mg·L^-1浓度处理)后,花丝萎缩,花药干瘪,出现大量不育花粉。GSC可以诱导白菜型油菜产生雄性不育,随着GSC浓度的增加,不育株数和失活花粉数也逐渐增加,在T7浓度,植株不育株率达86.49%,失活花粉率达89.30%;同时用此浓度处理后花粉囊发育不良,绒毡层细胞提前解体或随花粉粒退化一同消失,小孢子团紧贴内壁,数量变少。试验说明化学药物GSC对白菜型冬油菜具有一定的杀雄效果,同时杀雄效果与药物浓度有一定关系。     

接种外源生物菌剂后牛粪堆肥腐植酸变化规律

添加3种不同的外源生物菌剂对牛粪进行堆肥试验,通过测定堆肥过程中的温度、腐植酸的变化,研究了添加外源微生物对堆肥腐熟进程的影响,以及筛选出适合当地堆肥条件的生物菌剂。结果表明,添加3种外源微生物均对堆体快速升温及延长高温期有显著作用;菌剂2、菌剂3有效地加速了总腐植酸、水溶性腐植酸的转化与合成,但对游离腐植酸的作用并不显著;添加菌剂3处理的胡敏酸与腐殖化指数高于其他两个处理,且与对照差异显著。各处理的富里酸含量在堆肥结束时基本相同,外源菌剂对其并无影响。     

Induction of host defence enzymes by the endophytic bacterium Serratia marcescens,in banana plantlets

Pre-inoculation with the endobacterium Serratia marcescens (strain UPM39B3) induced the production of host defence enzymes such as peroxidase, polyphenoloxidase, phenylalanine ammonia lyase, total soluble phenols and lignothioglycolic acid in banana plantlets. The levels of these enzymes were evidently higher in plantlets pre-treated with the endobacterium compared to the control. The production of host-induced enzymes benefitted the crop plants as they may have a role in suppressing Fusarium wilt incidence in the plantlets. This was evident when plantlets pre-treated with the endobacterium showed a lower disease severity (50%) compared to diseased plantlets lacking the endobacterium (74%). The results of this study thus highlight the potential of the isolate Serratia marcescens (strain UPM 39B3) as a biological control agent for Fusarium wilt management in bananas, reducing disease severity via stimulation of host defences.     

稻草还田配施催腐菌剂对晚稻根际土壤微生物与酶活性及产量的影响

稻草还田有利于土壤的可持续耕作,但往往影响土壤的当季生产力。以五丰优T025为供试作物,红壤为供试土壤,在大田条件下研究了微生物制剂在稻草还田中对土壤中微生物数量和酶活性的影响,并以水稻农艺性状和产量检验了土壤的生产力。结果表明,稻草全量还田并添加微生物制剂能够显著提高土壤中细菌、真菌和放线菌的数量,增强蔗糖酶、脲酶、过氧化氢酶和纤维素酶的活力;提高晚稻的单穗粒数、结实率、千粒重和产量。微生物制剂在稻草全量直接还田中具有较好的应用前景。     

Organic and Mineral Fertilization: Effects on Physical Characteristics and Boron Dynamic in an Agricultural Soil

Abstract

The mineral and organic fertilizations on lettuce (Lactuca sativa L.) cultivation were investigated to understand the correlations between soil physical and mechanical indexes and boron (B) dynamic (adsorption, desorption, fractions) in soil. The fertilization with compost (derived by wine‐producing residues) and integrated fertilization (compost plus ammonium nitrate) increased the soil workability, as do the extent of aggregation, the water retention, and the cation exchange of the soil. The physical (colloids index, Ic) and mechanical (shear resistance, τ) properties showed a significantly higher value in compost and integrated fertilization plots. The biomass application to the soil influences the sorption B behavior, which is related to the soil shear strength and the compaction susceptibility; the Langmuir maximum adsorption for B was positively related with plastic deformation (De) and dry bulk density (Db) and negatively related to water infiltration (Wi), τ, and compressibility index (Cs).

The B desorption was not modified by the variation on soil mechanical resistance; no correlation was found between B desorption index and physical–mechanical parameters of the soil. The B fractions, not readily available for plants, occluded in aluminium (Al) and iron (Fe) oxyhydroxides (Ox‐B) and organically bound (OM‐B), were negatively correlated with colloid index (Ic), Wi, τ, and moisture content (U), and were positively correlated with De, Db, and compressibility index (Cp, related to organic‐matter content of the soil).