广西红壤木薯肥料多年定位试验（1989～1996）综合分析①

摘要

A long-term fertilizer trial on cassava from 1989-1996, including 2 cassava varieties (SC201 and SC205) and 15 fertilization treatments (chemical fertilizers and farmyard manure), to provide scientific basis for cassava fertilizing. Results showed that cassava yields and weight of shoot were both significantly different among years and cassava cultivars, respectively. The cassava yield of SC201 and SC205 increased significantly in 3/8 and 5/8 years, respectively, with the application of farmyard manure (FYM). Cassava yields were significantly improved, in most of the observed years (SC201 6/8, SC205 7/8), after NPK fertilizers were applied with the proportionate quantity according to the "suggested NPK fertilization", which is 100∶50∶100 kg/hm2 N∶P2O5∶K2O. The correlation of cassava yields and the NPK fertilizing amount could be fit with parabolic equation in 3/8 years and 6/8 years for SC201 and SC205, respectively. The shoot weight increased following a parabolic curve with the increase of NPK fertilization, while the starch content decreased. N fertilizer increased cassava yields in most of the years (5/8 and 8/8 years for SC201 and SC205, respectively). And quantity of N fertilizers and cassava yields could be fit with parabolic equation in 5/8 and 3/8 years for SC201 and SC205, respectively. The shoot weight was increased with N fertilizer applied. P fertilizers increased the yield of SC201 and SC205 in 3/8 and 5/8 years, respectively. The K fertilization increased the cassava yield of both varieties in 2/8 years, respectively, but significantly increased shoot weight in 3/4 years for each variety, respectively. Cassava yield and shoot weight was increased by N fertilization, N is the first limiting factor to cassava yield in the typical red soil;K fertilization can also increase shoot weight. Application of P fertilizer could increase the yield of SC205 in more years than K fertilizer. The shoot weight, yield, starch yield of SC201 was higher than those of SC205. Fewer yields were produced by SC205 than SC201, with more fertilization needed. Thus, variety should be considered in cassava fertilization. The optimum fertilization in this long-term trial was 50% (50∶25∶50 kg/hm2 N∶P2O5∶K2O ) of the "suggested NPK fertilization" + 5 t/hm2 of FYM (pig manure). The NPK application for SC201 and SC205 was 124∶62∶124 and 161.6∶50∶100 kg/hm2 N∶P2O5∶K2O respectively, if there were only chemical fertilizers to be applied.%1989～1996年在广西典型红壤上进行了肥料定位试验，试验有2个木薯品种(SC201和SC205)、15个施肥处理(包括有机肥，氮磷钾化肥)。结果表明院不同年份和品种的木薯鲜薯产量差异显著，茎叶重亦如此；SC201施用有机肥后3/8年有显著增产，而SC205有5/8年显著增产。 NPK的施用显著增加鲜薯产量， SC201的概率6/8， SC2057/8。且NPK施肥量能与SC201的产量在3/8年显著拟合， SC205则为6/8年。茎叶重随NPK的施用量增加呈抛物线上升趋势，淀粉含量随着NPK施用量增加而降低。施用氮肥在部分年份(SC201，5/8年；SC2058/8年)显著提高产量，且产量与施氮量能在部分年份用抛物线显著拟合(SC201，5/8年； SC2053/8年)。茎叶重随施氮量增加而显著增加；施用磷肥对SC201在3/8年有增产效果，对SC205在5/8年有显著增产。钾肥对2个品种的鲜薯产量仅2/8年有显著增产；但分别在3/4年显著提高了茎叶重。说明氮在大部分年份能显著增加鲜薯产量和茎叶重，氮是典型红壤木薯产量的第一限制因子；钾肥能提高茎叶重，施磷比施钾对SC205在更多年份能显著增产； SC201茎叶重、鲜薯产量、淀粉产量比SC205高； SC205比SC201需要更多的肥料，但是获得更小的产量。因此，木薯施肥应考虑品种差异，推荐的施肥量为50%(50∶25∶50 kg/hm2 N∶P2O5∶K2O)的推荐施肥量＋5 t/hm2的有机肥(猪粪)；纯施化肥时，推荐 SC201和 SC205的施肥量分别为124∶62∶124，161.6∶50∶100 kg/hm2 N∶P2O5∶K2O。