Cereal and other crops raised by means of such irrigation are watered at regular intervals from March to June, and what are known as "summer crops" from May till September. The return on irrigated land for wheat and barley sown is rarely more than ten-fold, usually much less. Side by side with this irrigation in some districts, and exclusively in some of the higher altitudes on the central Iranian plateau, between 6,000 and 8,000 feet, dry cultivation, dependent entirely on the rainfall, is practised. Dry cultivation is indeed the sole resource of the great alluvial Persian Gulf plain extending from the province of Khuzistan to the south ern extremity of Dashti district, and in the Sistan belt in the east. On the shores of the northern end of the Gulf the rainfall may average 12 inches at Bushire; and at Shiraz, 120 miles inland across the mountains, 13 inches, as compared with a bare 3 inches in the year at Isfahan on the central plateau.
Wheat and barley are sown after the ground, hard baked by the powerful summer sun, is sufficiently softened by the first rain which may be as early as the first week in November, or as late as the first week in January. In the case of barley reaping will not be later than the 15th to loth of April, while wheat is harvested from the end of April to the first days of May, roughly one month earlier than in upper Fars, and 21 months earlier than harvesting in the altitudes above 6,000 ft. A full ploughing season is reck oned by the peasants as 4o days. The all-important factor, in the dry cultivation as distinct from the irrigated crop, is a suc cession of regular and soaking rainfalls between February 15th and April ist, particularly about March 21st. If such timely rains occur (even if sowing should have been delayed till late Decem ber or early January), a yield of 20 times the quantity of seed sown is common, as compared with up to 12-fold in the trans montane districts of Fars: On the other hand, excellent rains dur ing November to January, are often followed by a hold-off of rain in late February and March, the result of which is a meagre harvest hardly returning the seed sown. Harvest records in the Persian Gulf zone may be summarized over cycles of 11 years as I good year, 2 to 3 medium, 4 poor and 2 or 3 extremely bad. In years of penury numbers of peasants migrate, from spring to autumn, to work in the date-gardens of the Shatt-el-Arab.
A law for re-assessment of the land-tax due from private prop erties, on a basis of 31- per cent of the average yield of four years, was passed in 1926; but such re-assessment by 1928 had covered only a small portion of the country. In 1925 the Ministry of
Finance estimated the total production of wheat in Persia at the equivalent of some 1,092,000 standard tons (of which Khurasan province 145,000; Azerbaijan province 145,000, Fars 87,50o; Kerman 72,500; Kermanshah 72,50o; Kurdistan 58,000); and of barley at 568,00o tons, while the figures of the Customs adminis tration, for the year March 1925-26 give the total export from Persia as wheat 2,46o, barley 43o standard tons, nearly all to Russia. Export duty 1 kran per 13o lb.
In years of fair harvest the price of wheat in provincial towns may be the equivalent of 5s. 6d. per cwt. and upwards, rarely much less.
The usual ploughing implement is of rough hewn wood with an iron shoe for share, drawn by a pair of bullocks or donkeys, furrows being rarely more than 3 to 4 inches deep; the seed is ploughed in, in most cases, on sandy soil not prepared by a pre liminary cleaning or manure. Reaping is by sickles, and the grain is trodden out from the straw by bullocks or asses on the thresh ing-floors of the Bible. Ridging in the European sense is not practised. By 1928, except perhaps for a few machines in the Karun valley, in the whole country south of Isfahan only two tractors had been introduced (and these by European farmers). The experience of the latter is that the deeper ridging by ma chinery, and ploughing before the rains begin make both for economy in and a stronger, heavier crop. In the Tehran dis trict the Government since 1921 has instituted farms for train ing students, and given exhibitions of farming machinery, while certain of the great magnates have imported tractors for their es tates; but, in general, agricultural machinery is rarely in use. The peasants, particularly in the south, look with no kindly eye on such improvements, and are inclined to thwart experiments or changes, the absence of skilled or reliable mechanics being an ad ditional obstacle to the use of agricultural machines.
Rice cultivation flourishes above all in the Caspian provinces, Gilan and Mazandaran, production there being estimated by the Ministry of Finance at the equivalent of some 230,000 standard tons. But, though this was considered eight-ninths of the whole production of Persia, in all parts where there is irrigation from rivers and springs (i.e., except in the Persian Gulf zone, Baluchistan and the east), and in the higher altitudes rice is grown mainly for local consumption, in the form of pilau chiefly, it being almost as much a staple food as bread, especially in the Cas pian zone.