82 SECOND THOUSAND QUESTIONS IN AGRICULTURE 



If you mean when the plant has highest value in itself it is while 

 the pods are still green and the stem yellowing a little at the base. 



Nettles as a Cover Crop. 



How could I get rid of nettles that persist in coming up thick 

 every winter in my orcliard and fairly smother out the cover crop, 

 notwithstanding the orchard is irrigated and kept quite clean through 

 the summer? 



Make a cover crop of the nettles. Run a mower over them as 

 soon as they get about a foot and a half high; let them make a second 

 growth and then plow all the stuff under in February or early March. 

 In this way you can keep the growth from getting too stemy and 

 hard to handle with the plow. Nettles are all right for humus. If 

 your irrigation water brings in the seed you are likely to be in the 

 nettle business right along unless you get the ditch company to clean 

 their ditch banks. If the seed does not come in the water your 

 summer and winter tillage will soon clean them out. 



Lupins and Bacteria. 



Is growth of small lupins on land an indication of sufficient nitrogen- 

 gathering bacteria being present for alfalfa? 



Presumably, yes. You can tell whether bacteria are operating by 

 taking up a young plant carefully and see if there are nodules on the 

 roots. Presumably also the presence of germs on lupins, bur clover 

 and other wild legumes equips the soil for alfalfa, beans, etc., or we 

 would not get the crops we do by planting without inoculation. 



Nitrogen Bacteria and Bur Clover. 



Will the nitrogen-producing bacilli of the bur clover live and 

 work on alfalfa? Would a soil solution containing tubercular roots of 

 bur clover be a satisfactory means of "inoculating" alfalfa seed? 



It is believed that the reason alfalfa succeeds so generally in 

 California is that the widespread bur clover has loaded the soil with 

 the proper bacteria. The earlier view that different legumes required 

 different bacteria for each of them is losing force in the face of recent 

 investigations. Whether you need to use bur clover soil solution is 

 doubtful. It is probable that the bacteria are already installed in 

 most California soils. 



Sweet Pea Straw. 



What is the best way of using sweet pea straw for fertiliser? 

 What crop would best follow sweet peas? How can the green aphis 

 be prevented from damaging a crop of sweet peas? 



When thoroughly dry, as it comes from gathering a seed crop, 

 the straw can be spread, disked to break it up, and plowed into a 

 heavy soil as soon as there is rain enough to deeply wet the soil. 



