黄麻秸秆及有机肥对滨海盐土生物性质的影响

为改善滨海盐土质量,通过黄麻秸秆还田及施用有机肥对盐土的改良试验,研究不同施用量的秸秆与有机肥配施分别对土壤酶活性、微生物的影响。结果表明:以3 600 kg/hm2秸秆施用量分别与有机肥施用量为2 400、3 600 kg/hm2配施时对土壤生物性质改良效应较为明显,土壤脲酶分别比对照增加53%和98%、蔗糖酶增加700%和825%、过氧化氢酶增加49%和65%、磷酸酶增加99%和161%、土壤微生物数量增加了5.8、9.5倍,其中,真菌增幅较大,两种方式下分别增加55.1、90.8倍。说明秸秆与有机肥配施能明显提高滨海盐土酶活性,增加土壤微生物数量,增强土壤生物学活性,从而提高土壤肥力。

黄麻秸秆还田及有机肥对滨海盐土的改良试验

通过黄麻秸秆还田及施用有机肥对滨海盐土的改良试验研究，结果表明，施用有机肥料和秸秆还田可以改善滨海盐土理化性质，降低土壤密度、pH值和盐分含量，提高土壤孔隙度，增加土壤有机质和养分含量。研究得出，秸秆施用量为3600kg／hm^2及有机肥施用量为1200—3600kg／hm^2时，对滨海盐土结构、盐分及pH等理化性质的综合改善作用最为明显。

稻草、黄麻纤维、棕榈叶的吸水性和腐解速率研究

由于地表覆盖物吸水特性直接影响径流产生过程,而其腐解特性又关系到地表覆盖物保水保土作用的持久性,因此本试验研究了在相同条件下稻草、黄麻纤维和棕榈叶分别在5 min,10 min,30 min和1 h,6 h,12 h,24 h内的吸水性差异以及100 d内的腐解情况。结果表明:在浸泡5 min和10 min时,吸水量为黄麻纤维>稻草>棕榈叶,而从30 min^24 h期间,则为稻草>黄麻纤维>棕榈叶。3种材料的吸水速率在5 min时最大,以后不断减小,且在24 h内未达到吸水饱和;在腐解100 d内,黄麻纤维腐解残留率最小,稻草最大,棕榈叶居中,三者都是前40 d腐解较快,黄麻纤维和棕榈叶在后期腐解趋于平缓,而稻草则在后期腐解速率有增快趋势;腐解过程中3种材料的土壤含水量、温度变化大部分情况差异不显著;C/N比都逐渐减小,后期基本趋于稳定。

Effect of Curing Treatments on Seven Key Farmers’ Yams (<i>Dioscorea</i>spp.) in Ghana

Curing of freshly harvested yams (Dioscorea spp.) is a process for wounded yams during harvest to heal. In this work the effectiveness of straw, polypropylene and jute sack on curing of seven key farmers’ yam varieties over a duration of 7, 14 and 21 days was studied. Seven key farmers’ yam varieties identified as Pona, Lariboko, Dente, Mutwumudoo, Serwah belonging to D. rotundata, Matches and Akaba belonging to D. alata were studied under different curing treatments. The percentage weight loss of yam tubers varied among the treatments over curing period. Curing under jute sack showed all yam varieties had weight losses less than 2.0%, within 7 days of curing. Five different varieties had weight loss less than 2.0% except Dente under the straw treatment. Mutwumudoo variety showed the highest water loss (8.4%) for polypropylene sheet and 6.9% for Lariboko in the control treatment. During 7 days curing the control and polypropylene treatment did not support yam curing. After 14 days of curing of tubers, similar tends were observed as in 7 days curing. After 14 days of curing under jute sack, percentage weight loss of the tubers ranges from 2.0% - 3.7%. In the straw treatment, the percentage weight loss ranges between 1.0% - 4.7% in all other varieties except Dente (D. rotundata) (8.2%). Polypropylene sheet treatment showed the highest percentage weight loss in Mutwumudoo variety (18.4%). A similar trend was observed for the yam tubers cured for 21days as percentage weight loss of tubers under jute sacks was 2.5 – 9.8%. Curing temperature and humidity ranged between 27&degC - 40&degC and 87% - 100% rh for yam tubers under the three different treatments of polypropylene, jute and straw. However, the control treatment recorded lower humidity of 60% - 80% rh. Curing material, duration, climatic conditions and yam varieties influenced curing and Serwah variety, which is a D. rotundata is the best bet yam variety to cure under jute sack for 7, 14 and 21 days of curing.