Although the spatial position has an important influence on the performance of a rain gage, the physical presence of the gage itself must be considered a hindrance to its operation. An obstruction to airflow in the vicinity of the gage, owing to the presence of the gage, results in disturbances in the local precipitation pattern in which the rainfall measurement is made. The airflow pattern data obtained in a study of a wind tunnel model and aerodynamic drag characteristics of water drops are used to perform a computer simulation on the movements of the drops as they approach the gage. These drop paths are analyzed to establish the effectiveness of the gage in measuring precipitation. If we use drop sizes of 1–5 mm in diameter, we find that the gage catches from 103 to 11% of the drops as the free stream velocity increases from 10 to 50 feet per second. In general, the decrease in catch is less pronounced as the drop size is increased.

C ONTOUR tillage is an important practice in the control of runoff and soil erosion. It is simple, inexpensive, and in many cases easily applied. Since contouring is generally used in connection with other conservation practices, such as soil treatment, crop rotations, terracing, and strip cropping, there are few results that show the effectiveness of the practice itself. This paper reports 9 years results on the effectiveness of contour farming on a productive Corn Belt soil. In addition to surface runoff and soil loss by erosion, the authors present a preliminary report on tile flow and plant nutrient losses in the tile drainage.

SynopsisLadino clover‐bromegrass sheep pastures irrigated with 4½ inches of water annually during a 4‐year period under a humid climate gave 23% more forage and 22% more lamb gain than nonirrigated postures. Forage production was increased an average of 0.16 ton per inch of applied water. Irrigation helped maintain clover in the pasture. Based on a replacement value of $25.00 per ton of dried forage and an annual irrigation cost of $4.03 per acre‐inch of water, irrigation resulted in a net loss of $13 per acre.

Synopsis Alfalfa‐Ladino clover‐bromegrass dairy pastures irrigated with 3 ⅓ inches of water annually during a 3‐year period under a humid climate produced 17% more forage and 18% more milk (because of increased carrying capacity) than those not irrigated. An inch of applied water increased forage production by 0.20 ton. Irrigation was not profitable, based on a replacement value of $25.00 per ton of dry forage produced and a cost of $5.11 per acre‐inch of water applied.

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