The experiment aimed to determine the optimal harvesting period for triticale in Northwestern He'nan Province,and to study the effects of the mowing period on the agronomic traits,yield,and nutritional quality of different triticale varieties.The experiment used six varieties as experimental materials:Zhong Si 3366(ZS3366),Zhong Si 1640(ZS1640),Zhong Si 1257(ZS1257),Zhong Si 1048(ZS1048),Shi Da No.1(SD1),and Gan Nong No.2(GN2).Four harvesting treatments were set up:Jointing stage(JNT),booting stage(HD),flowering stage(FLW),and milky stage(MLK),with the JNT treatment involving a second harvest of the regrowth at the milky stage.The results showed that as the growth period progressed,the plant height and dry hay yield continued to increase overall,while fresh hay yield first increased and then decreased.The fresh hay yield was in the order of HD＞JNT＞FLW＞MLK,and the dry hay yield was in the order of MLK＞FLW＞HD＞JNT.As the growth period progressed,the nutritional quality of the ryegrass decreased.Compared with JNT,the crude protein content and relative feed value of MLK decreased,while the content of acid detergent fiber and neutral detergent fiber increased.The crude protein content was extremely positively correlated with moisture and feed value(P＜0.01),and extremely negatively correlated with the content of acid detergent fiber and neutral detergent fiber(P＜0.01).The study indicates that SD1 has a higher comprehensive evaluation at different harvesting stages compared to other varieties,and the plant height,dry hay yield,and crude protein yield during the FLW stage are all higher than those of other varieties.Considering both yield and nutritional quality,the optimal harvesting period for triticale in the Northwestern He'nan Province is the flowering stage,and the variety SD1 has outstanding comprehensive traits,making it suitable for planting and promotion in this area.
The intrinsic mechanism underlying the changes in soil enzyme activities(urease,alkaline phos-phatase,and sucrase)in response to simulated precipitation alterations and their relationship with soil nu-trient supply conditions were investigated in the desert grassland of Inner Mongolia.Four precipitation gradients were set based on the average precipitation levels over several years:a 50％reduction in natural precipitation(P-50％),a control group(PCK),a 50％increase in natural precipitation(P+50％),and a 100％increase in natural precipitation(P+1oo％).Results indicated significant differences in the sensitivity of ure-ase,alkaline phosphatase,and sucrase activities to water availability in the desert grassland of Inner Mon-golia.Increasing precipitation significantly enhanced the activities of urease(17.36％),alkaline phospha-tase(9.9％),and sucrase(34.85％)in the soil layer at a depth of 10～20 cm,while decreased precipitation only significantly reduced alkaline phosphatase activity.All three soil enzymes are significantly correlated with available phosphorus and total nitrogen(P＜0.05),while an increase in available phosphorus de-creased the total potassium content.Overall,decreased precipitation significantly reduced alkaline phospha-tase activity(P＜0.01),while sucrase activity exhibited a significant increase followed by a significant de-crease with increasing precipitation gradients(P＜0.05),and urease activity showed a steady increase.Soil enzymes indirectly promoted soil nutrient content,the excessive nutrients exert an inhibitory effect on each other.
To investigate the feasibility of developing litchi leaves as silage, we determined the fermentation quality of four varieties of litchi leaves (including "Wanpu", "Wuyejiu", "Tongzai" and "Zhuangyuanhong") ensiled with or without Lactobacillus plantarum on day 3, 7, 14 and 30. The in vitro dry matter digestibility and gas production of litchi leaves silages were also determined after 30 days of ensiling. The results showed that Lactobacillus plantarum significantly reduced pH value (p < 0.01), inhibited coliform bacteria, and reduced the production of ammonia nitrogen (p < 0.01) in all the four kinds of litchi leaves silage. Moreover, Lactobacillus plantarum treated litchi leaves ("Wanpu" and "Zhuangyuanhong") had lower yeasts than the untreated litchi leaves during ensiling. The number of molds in Lactobacillus plantarum treated groups ("Tongzai" and "Zhuangyuanhong") was below the detected level after 30 days ensiling, which was lower than that of the untreated groups. The addition of Lactobacillus plantarum also contributed to improving IVDMD and markedly reduced (p < 0.01) gas production of all litchi leaves silages. Conclusions: Lactobacillus plantarum can improve the fermentation quality and in vitro digestion characteristics of litchi leaves silage. Developing litchi leaves as silage material is a feasible way to recycle litchi leaves.
为探究野牛草(Buchloe dactyloides)种质的变异规律和遗传多样性,筛选优良种质资源,本研究选取50份野牛草种质资源的种子,对其形态特征、质量特征以及萌发特性等不同方面进行研究.结果表明:野牛草种子的生物学性状在不同种质资源间均存在显著性差异(P<0.05),具有丰富的遗传变异和改良潜力.种子各生物学性状之间存在一定的相关性;基于不同性状指标进行聚类50份种质分为3大类群,依此可以筛选出7份性状表现优良的种质材料.当年采收的野牛草各种质资源的种子均具有较高生活力,但在自然条件下其平均出苗率小于10％,存在明显休眠现象.剥除颖苞结构是打破野牛草种子休眠的前提,但去除颖苞的颖果仍需引发剂处理才能大幅度促进种子萌发,其中以去除颖苞结构结合GA3溶液浸种的引发效果最好,且以2000 mg·L-1浓度为最佳,野牛草种子的休眠基本可以完全解除.
我国的"碳中和"战略将推动西北荒漠区太阳能资源的大规模利用.光伏基地的下垫面结构变化对荒漠土地植物生长的生态要素将产生什么影响,目前尚缺乏系统性认识.本文以腾格里沙漠南沿宁夏中卫市的光伏产业园区为例,通过分析卫星遥感植被指数和已有文献资料发现:2011-2021年间园区内有植被覆盖的像素单元从近乎为0增长至约33％,光伏阵列的建设改变下垫面的能量、温湿度和风场等生态因子是促使植被由无到有发育的决定因素.在满足2060年我国约4.0～4.3万亿kWh光伏发电需求的前提下,最可能情境的光伏建设用地需求为2.4～4.0万km2,可促进约1.6～2.6万km2荒漠土地的植被发育.这虽不足以根本改变西北荒漠区的生态格局,但继续深入研究光伏基地中生态因素的变化和效应,对认识西北荒漠区植被发育机制、生态阈值和水资源利用的可持续性有重要意义.
