However, if your soil is hard, sweet potatoes can be planted in small hills about 30 to 40 cm high. The plants should be one meter apart. This will prevent rainwater from collecting around the roots. Standing water can cause the tubers to rot.

不过,如果你的土地粘重,也可种在垒成30至40厘米高的土堆上,株距保持1米。这样,根系周围不至于积水。积水会导致块根腐烂。

属类：行业术语-农业-农作物

If your soil contains a lot of nitrogen, the plants will produce many stems and leaves, but few tubers. So if your soil is too rich, cut off some of the plant stems and leaves. This will permit the plants to produce more tubers.

如果土地含氮过多,植株会长出过多的茎叶,而结薯却很少。所以,如果土地太肥,把茎叶剪去一些,这样反而结薯更多。

属类：行业术语-农业-农作物

You should harvest sweet potatoes when the leaves turn yellow. Carefully dig the tubers out of the soil. Put them in the sun to dry.

甘薯叶转黄的时候,就该收获了。把薯块细心地挖出来,放在太阳下曝晒。

属类：行业术语-农业-农作物

When they are dry, put them in the cool, dry, dark storage area.

晒干后,放到凉爽、干燥、阴暗的地方贮藏。

属类：行业术语-农业-农作物

If you are growing sweet potatoes for your own use, plan carefully. The tubers can be kept for only two to three months after harvesting.

如果你种甘薯是为了自家消费,应作周密安排。甘薯收获后只能保存两三个月。

属类：行业术语-农业-农作物

since wheat is grown all over the world, there must be many varieties.

既然世界上到处都种有小麦,种类必定很多吧?

属类：行业术语-农业-农作物

Well, one method of classifying them is by the number of chromosomes, or carriers of heredity, in their sex cells.

小麦分类的方法之一是根据它们性细胞内染色体的数目,染色体是遗传的载体。

属类：行业术语-农业-农作物

Wheats are called diploids when they have seven chromosomes, tetraploids when they have fourteen, and hexaploids when they have twenty-one.

其性细胞具有7条染色体的小麦称为二倍体;具有14条染色体的称为四倍体;具有21条的称为六倍体。

属类：行业术语-农业-农作物

aI1 of our common or bread wheats, whether winter or spring varieties, are hexaploids. So are the spelt wheats.

我们的普通小麦,不论是冬性品种还是春性品种,全都是六倍体。斯卑尔脱小麦也是六倍体。

属类：行业术语-农业-农作物

What are the names of some of the others?

另外那些小麦还有些什么名称?

属类：行业术语-农业-农作物