202 STATE BOAED OF AGEICULTUKE. 



The seed must be unifoi'in ; the crops must be sowed the same day, cultivated 

 on the same days in the same manner ; they must be harvested at the same time 

 and weighed when they are of a uniform state of dryness. One day in time of 

 planting has been known to make a very great difference in the yield of some 

 crops under certain circumstances, perhaps owing to rain or other sudden change 

 of weather. The spaces of ground occupied by each must be exactly alike. 

 The space between any plats must not escape notice. It may affect the crops 

 differently if weeds or grass are allowed to grow. An experiment should be 

 made as simple as possible, only attempting to decide one thing at a time. 



Without stopping to give all the reasons, our English friends have decided 

 that plats of about ono-twentieth of an acre are of suitable size for testing fer- 

 tilizers. Scattered among them like spots on a checker board should be some 

 plats without the application of any fertilizer. 



On account of the variable results caused by varying seasons and many other 

 causes, to make experiments really valuable and decisive, they should be con- 

 tinued often for ten years or more, and repeated in different parts of the country. 

 We must be careful about drawing incorrect conclusions, or conclusions from 

 single experiments or from imperfect data of any kind. I have often been sur- 

 prised at the hasty conclusions people have drawn from some of my experi- 

 ments. 



Suppose we desire to try some experiments on apple trees in different modes 

 of culture. We may have one hundred trees of the same variety, all planted at 

 the same time and treated about alike for some years. Yet, even on what we 

 call a uniform soil, the trees will not make a uniform growth. Some of them 

 will "very likely die. Some will bear earlier than others, and perhaps no two 

 will bear equal quantities of fruit of the same quality. How much of this dif- 

 ference to attribute to the soil, we cannot tell. How much the top is affected 

 by the stock upon which it was grafted we do not know. Perhaps each tree 

 has some other peculiarities aside from those mentioned. Some trees will bear 

 fruit of better color than others. Some will produce fruit of superior flavor, 

 even when compared with others of the same variety in the same orchard. 



The health, growth, peculiarities, yield, and quality of fruit of a tree depend 

 upon a large number of conditions intimately interwoven. 



Some one may think that this is a discouraging side of the question, — that I 

 have greatly exaggerated the difficulties of exact experimenting in agriculture or 

 horticulture. 



If he doubt it now, he will not doubt it after digging and weighing each hill 

 of potatoes in several rows for several years, treated alike so far as he can judge. 

 He might be equally surprised at the variation in yield of corn or wheat, or any 

 other crop, if carefully weighed and compared on different seasons. 



Experiments on feeding animals are of an equally delicate and difficult nature. 

 Is it too much to say that many things we want to know about feeding animals 

 and the use of fertilizers will not be settled for many years to come? 



The chemist and physicist well understand the w^orking of exact experiments 

 in their laboratories. Some chemist has said that no experiments compare in 

 difficulty with those the farmer may be required to make. 



On account of the great difficulties and expense and time required, 1 doubt 

 whether the results will yet warrant us in making many such experiments. I 

 doubt whether the time has yet arrived for our farmers to make profitable use 

 of the results. I think many have over-estimated the results likely to be reached 

 in a short time. 



